Page 1 Model 2701 Ethernet-Based DMM / Data Acquisition System User’s Manual 2701-900-01 Rev. G / February 2016 *P2701-900-01G* 2701-900-01G A G r eat er Me as ur e o f Co n f id e n c e...
Page 2 Model 2701 Ethernet-Based DMM / Data Acquisition System User’s Manual ©2002-2016, Keithley Instruments All rights reserved. Cleveland, Ohio, U.S.A. Document Number: 2701-900-01 Rev. F / February 2016...
Page 3 Service personnel are trained to work on live circuits, perform safe installations, and repair products. Only properly trained service personnel may perform installation and service procedures. Keithley Instruments products are designed for use with electrical signals that are rated Measurement Category I and Measurement Category II, as described in the International Electrotechnical Commission (IEC) Standard IEC 60664.
Page 4 themselves from the risk of electric shock. If the circuit is capable of operating at or above 1000V, no conductive part of the circuit may be exposed. Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance- limited sources.
Page 5 (note that selected parts should be purchased only through Keithley Instruments to maintain accuracy and functionality of the product). If you are unsure about the applicability of a replacement component, call a Keithley Instruments office for information.
Page 6: Table Of Contents
Safety symbols and terms ..............1-2 Inspection ..................... 1-2 Battery ....................1-3 Options and accessories ..............1-3 Model 2701 features ................... 1-6 Plug-in switching modules ................1-7 Pseudocards ..................1-7 Identifying installed switching modules ..........1-7 Front and rear panel familiarization ..........(QS1) 1-10 Front panel summary .................
Page 7 Table of Contents Model 2701 Ethernet-Based DMM / Data Acquisition System Connections..................2-5 Pseudocards..................2-6 Channel assignments.................. 2-6 System channel operation................2-7 2-wire functions..................2-8 4-wire functions (paired channels) ............2-9 Controlling the system channel............2-10 Non-amp and non-measure switching modules ......... 2-14 Multiple channel operation ................
Page 8 Model 2701 Ethernet-Based DMM / Data Acquisition System Table of Contents 4-wire common-side (CSID) ohms measurements (7701 module) ..3-32 Temperature measurements ..............3-33 Thermocouples................... 3-33 Thermistors ..................3-36 4-wire RTDs..................3-37 Connections ..................3-38 Temperature measurement configuration........... 3-42 Temperature measurement procedure ..........3-45 Frequency and period measurements ............
Page 9 Table of Contents Model 2701 Ethernet-Based DMM / Data Acquisition System Basic operation ..................5-2 Remote programming — rel ..............5-4 Math ......................5-7 mX+b ....................5-8 Percent ....................5-9 Reciprocal (1/X) .................. 5-10 Basic operation ................... 5-11 Remote programming — math ............5-12 Ratio and channel average ...............
Page 10 Model 2701 Ethernet-Based DMM / Data Acquisition System Table of Contents Buffer ....................7-27 Scanning commands................7-27 Scanning programming example............7-32 Scanning examples................... 7-32 External trigger scan ................7-32 Monitor scan..................7-35 Triggering ....................8-1 Trigger model ....................8-2 Idle......................8-2 Control source and event detection............
Page 11 Table of Contents Model 2701 Ethernet-Based DMM / Data Acquisition System Separate function setups ..............10-3 DCV input divider................10-3 Multiple channel operation..............10-3 System commands..................10-3 Interface....................10-3 Password .................... 10-4 Battery ....................10-5 Miscellaneous system commands ............10-6 Ethernet setup ...................
Page 12 Model 2701 Ethernet-Based DMM / Data Acquisition System Table of Contents Service request enable register............11-9 Status byte and service request commands........11-10 Status register sets ................. 11-10 Register bit descriptions ..............11-11 Condition registers ................11-17 Event registers ................. 11-18 Event enable registers..............
Page 13 Table of Contents Model 2701 Ethernet-Based DMM / Data Acquisition System Connections and wiring ................B-4 Screw terminals ................... B-4 Wiring procedure ................. B-6 Typical connections ................B-8 Connection log................... B-10 Status and Error Messages ..............C-1 Signal Processing Sequence and Data Flow .........
Page 14 Model 2701 Ethernet-Based DMM / Data Acquisition System Table of Contents Visual Basic and CVI (C) examples ............G-2 LabVIEW examples ................. G-12...
Page 15: Getting Started
Power-up — Covers line power connection, line voltage setting, fuse replacement, power line frequency, and the power-up sequence. • Display — Provides information about the display of the Model 2701. • Defaults and user setups — Lists the *RST and factory default settings, and cov- ers the three setup configurations available to the user.
Page 16: General Information
Contact information Worldwide phone numbers are listed at the front of this manual. If you have any questions, please contact your local Keithley representative or call a Keithley Application Engineer at 1-800-348-3735 (U.S. and Canada only). Safety symbols and terms...
Page 17: Battery
The battery is warranted for 90 days. However, at 23°C, the battery will typically last three years. See Section 3 of the Model 2701 Service Manual to replace the battery. The Keithley part number for the battery is BA-52.
Page 18 Getting Started Model 2701 User’s Manual Model 7705 — This control module provides 40 independent 1-pole switching (SPST) channels that are isolated from the internal DMM. Model 7706 — This all-in-one module provides 20/10 channels of 2/4-pole input, 16 digital outputs, two analog outputs, and one 32-bit counter with gating and totalizer.
Page 19 Control software and software drivers for the Model 2701 are available on the Keithley website: www.tek.com/keithley. Rack mount kits Model 4288-1 single fixed rack mount kit — Mounts a single Model 2701 in a standard 19-inch rack. Model 4288-2 side-by-side rack mount kit — Mounts two instruments (Models 182, 428, 486, 487, 2000, 2001, 2002, 2010, 2400, 2410, 2420, 2430, 2700, 2701, 6430, 6517A, 7001) side-by-side in a standard 19-inch rack.
Page 20: Model 2701 Features
The Model 2701 has two slots that will accommodate Keithley Model 7700 series switch- ing modules (Table 1-1). Each channel of a switching module that is closed or scanned is measured by the Model 2701. For scanning, each channel can have its own unique setup (i.e., function, range, digits, etc.).
Page 21: Plug-In Switching Modules
Model 7700, 7701, 7702, 7703, 7705, 7708, 7709, 7710, 7711, or 7712 switching module is removed while the Model 2701 is on, the instrument will operate as if the module is installed. That is, the Model 2701 will operate as if the pseudocard is installed.
Page 22 Getting Started Model 2701 User’s Manual Table 1-1 Model 77xx series switching modules Model 7700 Model 7701 Model 7702 Model 7703 2-pole Operation 20 channels 32 channels 40 channels 32 channels 4-pole Operation 10 channel pairs 16 channel pairs 20 channel pairs...
Page 23 Model 2701 User’s Manual Getting Started Table 1-1 (continued) Model 77xx series switching modules Models 7711 Model 7709 Model 7710 and 7712 2-pole Operation 8-channels 20 channels 4-pole Operation 4 channel pairs 10 channel pairs 1-pole Operation N/A 8 channels...
Page 24: Front And Rear Panel Familiarization
Use to select a shifted function or operation. LOCAL Cancels remote mode. SHIFT + LOCAL disables keyclick. POWER Power switch. In position turns 2701 on (I), out position turns it off (O). 2 Function and operation keys: Top Row Unshifted Selects DC voltage measurement function.
Page 25 Restores a default setup (factory or *RST) or a saved setup. Enables/disables buffer auto clear, auto scan, and auto channel configuration. Sets timestamp, date, and time. Displays serial number of Model 2701. CONFIG Selects and configures a simple scan or an advanced scan.
Page 26 1-12 Getting Started Model 2701 User’s Manual 3 Range keys: Unshifted Dual function—Selects the next higher/lower measurement range for the selected function. When in a menu, these keys make selections or change values. AUTO Enables/disables autorange for the selected function.
Page 27: Rear Panel Summary
Amps fuse holder Holds current fuse for front panel amps input. Rear panel summary The rear panel of Model 2701 is shown in Figure 1-2. As shown, a slot cover is installed on slot 2. Figure 1-2 Model 2701 rear panel...
Page 28 100V/120V/220V/240VAC at line frequencies of 50 or 60Hz. 6 Slot 1 and Slot 2 Two slots to accommodate Keithley Model 77xx series switching modules. The Model 2701 is shipped from the factory with slot covers installed. Please note additional slot covers can be requested from Keithley Instruments.
Page 29: Power-Up
Line power frequencies – 45Hz to 66Hz and 360Hz to 440Hz. Line power connection Follow the procedure below to connect the Model 2701 to line power and turn on the instrument. Check to see that the line voltage indicated in the window of the fuse holder assem- bly (Figure 1-3) is correct for the operating voltage in your area.
Page 30: Line Frequency
80VA MAX Line frequency The Model 2701 will operate at line frequencies from 45Hz to 66Hz and 360Hz to 440Hz. There are no user-settings for line frequency. It is automatically sensed at power-up. The following command can be used to read the line frequency: SYSTem:LFRequency? ' Query power line frequency.
Page 31: Power-Up Sequence
The entire power-up cycle takes approximately 30 seconds. Do not attempt to communicate with the Model 2701 during this time period. Turn on the Model 2701 by pressing in the front panel POWER button. While booting up, the following messages will be briefly displayed:...
Page 32 After the power-up sequence, the instrument begins its normal display of readings. NOTE The serial number of the Model 2701 can be displayed by selecting the SNUM item of the SETUP menu. Press SHIFT and then SETUP to access the menu. For remote operation, the serial number can be read using the *IDN? command (see Section 12 for details).
Page 33: Keyclick
Appendix C. Remote programming — display Using remote programming, the Model 2701 can display a custom ASCII message (up to 12 characters). Also, the front panel display and controls can be disabled. Display commands...
Page 34 All front panel controls (except LOCAL) are disabled. Normal display operation can be resumed by using the ENABle command to enable the display or by putting the Model 2701 into local mode (press LOCAL). Programming example The following command sequence displays the text message “TESTING”: DISP:TEXT:DATA 'TESTING' ' Define text message.
Page 35: Defaults And User Setups
1-21 Defaults and user setups Model 2701 can be restored to one of two default setup configurations (FACTory or *RST) or five user-saved (SAV0, SAV1, SAV2, SAV3, or SAV4). As shipped from the factory, Model 2701 powers up to the factory (FACT) default settings.
Page 36 If the settings for a user setup or power-on setup do not match the switching module types presently installed in the Model 2701, error +520 (Saved setup scancard mismatch) occurs when the setup is recalled. The scan list will reset to the factory defaults and all channels will open.
Page 37 Model 2701 User’s Manual Getting Started 1-23 Table 1-4 Default settings Setting Factory *RST Set Diff Auto channel configuration No (off) No effect Autozero Buffer No effect No effect Auto clear Yes (on) No effect Channel Average Closed channels None...
Page 38 1-24 Getting Started Model 2701 User’s Manual Table 1-4 (continued) Default settings Setting Factory *RST Set Diff Limits LO Limit 1 HI Limit 1 LO Limit 2 HI Limit 2 Line Synchronization Math mX+B Scale Factor Offset Units “X” “X”...
Page 39 Model 2701 User’s Manual Getting Started 1-25 Table 1-4 (continued) Default settings Setting Factory *RST Set Diff RS-232 No effect No effect Baud rate No effect No effect Flow control No effect No effect Terminator No effect No effect Scanning...
Page 40: Remote Programming - Default And User Setups
Programming example *SAV 2 ' Save present setup in memory location 2. SYST:POS SAV2 ' Specify SAV2 setup as the power-on setup. *RST ' Return 2701 to RST defaults. *RCL 2 ' Return 2701 to setup stored in memory location 2.
Page 41: Remote Programming Information
Optional command words — In order to be in conformance with the IEEE-488.2 stan- dard, Model 2701 accepts optional command words. Any command word that is enclosed in brackets ([]) is optional and does not have to be included in the program message.
Page 42: Quick Start Exercises
• Trigger and return readings — remote programming. NOTE For remote operations, you can use the internal web page of the Model 2701 to send commands, queries, and take readings. See “Internal web page” in Section 10 for details. WARNING For the exercises, it is not necessary to connect an input signal or DUT to the instrument (front panel inputs or switching module inputs).
Page 43: Basic Dmm Measurements - Front Panel Inputs
See Section 3 for details on basic DMM operation. The Model 2701 is shipped from the factory to power-up to factory defaults. The instru- ment powers up to a setup that continuously measures DC volts. Some of the default set- tings for the DCV function include auto range enabled, 6½-digit resolution, filter enabled,...
Page 44 1-30 Getting Started Model 2701 User’s Manual Exercise 1 — Basic DMM measurements The exercise in Table 1-6 measures ACV on the 10V range and stores 15 readings in the buffer. Table 1-6 Exercise 1—Measure AC volts - store readings in buffer...
Page 45: Closing And Opening Channels - System Channel Operation
• For a 2-wire function (i.e., DCV), closing a system channel connects the input to DMM Input of the Model 2701. Figure 1-4 shows system channel 1 closed. For the Ω2 function, the resistance (DUT) would be connected to DMM Input as shown Figure 1-4.
Page 46 When a system channel is closed, the channel number will be displayed on the Model 2701. The slot number for the module is also displayed. For example, “103” indicates that system input channel 3 for a module in slot 1 is closed.
Page 47 Model 2701 User’s Manual Getting Started 1-33 Figure 1-6 shows the front panel keys used to close and open system channels. Figure 1-6 Front panel keys to close and open system channels CLOSE OPEN A. Sequencing through B. Specifiying channel to close C.
Page 48 1-34 Getting Started Model 2701 User’s Manual Exercise 2 — Closing and opening channels (system channel operation) The exercise in Table 1-7 demonstrates a sequence to close and open channels of a Model 7700 installed in slot 1 of the mainframe.
Page 49: Simple Scanning
NOTE The Model 2701 can also be configured to run an advanced scan. For an advanced scan, each channel can have its own unique setup (i.e., function, range, etc.). Advanced scanning is covered in Section 7.
Page 50 1-36 Getting Started Model 2701 User’s Manual Figure 1-7 Simple scan operation Step 1. Configure simple scan: Step 2. Run simple scan: CONFIG Step 3. Disable scan mode: HALT For remote programming, the following commands are used for simple scanning: ROUTe:SCAN <clist>...
Page 51 Model 2701 User’s Manual Getting Started 1-37 Exercise 3 — Simple scanning The scanning example in Table 1-8 assumes a Model 7700 installed in slot 1 of the mainframe. The scan will use default settings (DCV) to scan eight channels and store the readings in the buffer.
Page 52: Trigger And Return Readings - Remote Programming
1-38 Getting Started Model 2701 User’s Manual Trigger and return readings — remote programming There are several commands used to trigger and return readings. The proper commands and sequence to use depend on the trigger state (continuous or non-continuous) and what you are trying to accomplish.
Page 53 Model 2701 User’s Manual Getting Started 1-39 Exercise 4 — Trigger and return a single reading Exercise 5 — Trigger and return multiple readings Trigger controlled measurements — The instrument is typically used in a non- continuous trigger mode. In this mode, commands are used to trigger one or more readings.
Page 54 1-40 Getting Started Model 2701 User’s Manual Figure 1-9 Exercise 5 — Trigger and return multiple readings Trigger Configuration Trigger and Return Readings...
Page 55 Model 2701 User’s Manual Getting Started 1-41 Exercise 6 — Return a single reading (continuous triggering) Readings can be returned while the instrument is in the continuous measurement (trigger) mode. Each time a read command is sent, the latest reading is returned. Exercise 6 in Figure 1-10 provides a command sequence to return a single reading while in the continu- ous trigger state.
Page 56: Closing And Opening Switching Module Channels
• Switching module installation and connections — Explains how to install a switching module (or pseudocard) into the Model 2701 mainframe. Also explains where to find connection information which should only be performed by qualified service personnel.
Page 57: Close/Open Overview
Close/Open Switching Module Channels Model 2701 User’s Manual Close/open overview NOTE For remote operations, you can use the internal web page of the Model 2701 to send commands, queries, and take readings. See “Internal web page” in Section 10 for details. NOTE This section covers basic close/open operations for switching module channels.
Page 58 Model 2701 User’s Manual Close/Open Switching Module Channels NOTE The Model 2701 can scan switching module channels. Each channel in the scan can have its own unique setup configuration. Scanning is covered in Section 7. NOTE When a setup is saved as a user setup (SAV0, SAV1, SAV2, SAV3, or SAV4), closed channels are also saved.
Page 59: Switching Module Installation And Connections
Perform the following steps to install a switching module into the Model 2701 mainframe: Turn the Model 2701 off and disconnect the power line cord and any other cable connected to the rear panel. Position the Model 2701 so you are facing the rear panel.
Page 60: Connections
• Before making or breaking connections to the switching module, make sure the Model 2701 is turned off and power is removed from all external circuitry. • Do not connect signals that will exceed the maximum specifications of switching modules.
Page 61: Pseudocards
A pseudocard cannot be installed from the front panel. However, once it is installed you can take the Model 2701 out of remote and use the front panel. Pressing the LOCAL key takes the Model 2701 out of remote.
Page 62: System Channel Operation
DMM Input of the Model 2701. The system channel number is displayed on the Model 2701. For a 4-wire function (i.e., Ω4), the paired channel for the system channel is internally connected to DMM Sense. The paired channel is not displayed on the Model 2701.
Page 63: 2-Wire Functions
Figure 2-1 shows an example of how the system channel is connected to the DMM Input of the Model 2701. Assume a Model 7700 switching module is installed in slot 1 of the mainframe. When channel 101 is closed using the system channel close keys, both the Channel 1 relay and the backplane isolation relay (Channel 25) close to connect the channel to the DMM.
Page 64: 4-Wire Functions (Paired Channels)
DMM Sense. Also, note in Figure 2-2 that the Channel 23 relay closes to isolate channel 1 from channel 11. The complete simplified schematic of Model 7700 is provided in Figure 2-12. Figure 2-2 4-wire system channel connections to Model 2701 DMM Model 2701 Slot 1 Model 7700 Switching Module...
Page 65: Controlling The System Channel
2-10 Close/Open Switching Module Channels Model 2701 User’s Manual Controlling the system channel When a measurement channel is closed, a previous system channel (and, for a 4-wire function, its paired channel) is first opened. The closed measurement channel becomes the system channel.
Page 66 Model 2701 User’s Manual Close/Open Switching Module Channels 2-11 Press ENTER to display the prompt to close a channel (CLOSE CH: XXX). Using , , and , key in the three-digit channel you want to select. Press ENTER. The channel closes and the CHAN annunciator turns on.
Page 67 The ALL menu option of the OPEN key opens all channels for all switching modules installed in the Model 2701 (Figure 2-5). For example, if a Model 7700 switching module is installed in slot 1, OPEN: ALL will open all measurement channels (101 to 120, 121, and 122), the backplane isolation channels (124 and 125) and the 2-pole/4-pole channel (123).
Page 68 Model 2701 User’s Manual Close/Open Switching Module Channels 2-13 Table 2-1 System channel control commands Commands Description ROUTe:CLOSe <clist> Specify one measurement channel to close. ROUTe:CLOSe:STATe? <clist> Query closed channels in specified list (1 = closed). ROUTe:CLOSe? Returns a <clist> of closed measurement channels.
Page 69: Non-Amp And Non-Measure Switching Modules
The following example assumes a Model 7700 installed in slot 1, and the Ω4 function of the Model 2701 is selected. This command sequence connects channel 101 and its paired channel (111) to DMM Input and Sense as shown in Figure 2-2.
Page 70 Making amps measurements — In order to perform amps measurements, you must use the front panel inputs of the 2701 mainframe. You can still use the non-amps module for other aspects of the test, but you must use multiple channel operation to close channels.
Page 71: Multiple Channel Operation
Whatever channels were previously closed, remain closed. • A channel closed using multiple channel operation is not displayed on the Model 2701. Also, the CHAN annunciator does not turn on when a channel is closed. • Opening a channel using multiple channel operation has no affect on other closed channels.
Page 72: Controlling Multiple Channels
Most switching modules use latching relays. That is, closed channels remain closed when the Model 2701 is turned off. Never handle a switching module that is connected to an external source that is turned on. Turn off all power sources before (1) making or breaking connections to the module, and (2) installing (or removing) the module into (or out of) the Model 2701.
Page 73 2-18 Close/Open Switching Module Channels Model 2701 User’s Manual CLOSE key (MULTI menu option) The MULTI menu option for the CLOSE key can be used to close any individual channel in the mainframe (Figure 2-6). Perform the following steps to close a channel: NOTE Channels closed by the MULTI option of the CLOSE key are not displayed.
Page 74 NOTE If the channel you open using OPEN: MULTI is the system channel (channel number displayed on the Model 2701), the channel will open, but the system channel number will still be displayed (see “Multiple channel operation anomalies,” page 2-22).
Page 75 2-20 Close/Open Switching Module Channels Model 2701 User’s Manual Remote programming — Multiple channel control commands The commands to close and open the system channel are listed in Table 2-2 Table 2-2 Multiple channel control commands Commands Description ROUTe:MULTiple:CLOSe <clist>...
Page 76 Model 2701 User’s Manual Close/Open Switching Module Channels 2-21 ROUTe:MULTiple:OPEN <clist> With this command, you can open one or more switching module channels. When you send this command to open the channels specified in the <clist>, only those listed channels will open. Channels not specified are not affected.
Page 77: Multiple Channel Operation Anomalies
Use the MULTI option for the OPEN key, open channel 101. Even though channel 101 is still being displayed on the Model 2701, it is channel 102 that is actually connected to the DMM Input (channels 102 and 125 closed).
Page 78 Channel 124 (connects channel 111 to DMM Sense). • Channel 123 (isolates channel 101 from channel 111). The Model 2701 will display the 1kΩ reading for system channel 101. Remote programming: ROUT:CLOS (@101) Using the MULTI option for the OPEN key, open channel 111. This opens the connection to DMM Sense and causes an OVRFLW reading.
Page 79: Dual Independent Multiplexers
(channels 11 through 20). For the dual multiplexer configuration, only Multiplexer A channels can be internally connected to the DMM of the Model 2701. For the Model 7700, closing channel 25 allows channels 1 through 10 to be measured by the DMM.
Page 80 Model 2701 User’s Manual Close/Open Switching Module Channels 2-25 Figure 2-8 Dual multiplexer configuration (Model 7700) Ch 1 Multiplexer A Channels (1x10) 2–9 Ch 10 Ch 25 Input Ch 23 Model 2701 (Closed) Ch 24 Ch 11 Sense Channels Multiplexer B...
Page 81 This application demonstrates how to use the Model 7700 as a dual multiplexer to bias and measure 10 DUT. An external source powers DUT, while the DMM of the Model 2701 measures the output of the DUT. To prevent overloading of the external source, each DUT is powered (and measured) separately.
Page 82 Model 2701 User’s Manual Close/Open Switching Module Channels 2-27 Figure 2-9 Dual multiplexer application connections Model 2701 Model 7700 Switching Module External Sense Source Ch 1 Ch 2 Ch 10 Input Ch 25 Ch 23 (Closed) Ch 11 Sense Ch 24...
Page 83 2-28 Close/Open Switching Module Channels Model 2701 User’s Manual Figure 2-10 Testing DUT 1 Model 2701 Model 7700 Switching Module External Sense Source Slot 1 Ch 25 Ch 1 Input Ch 23 (Closed) Ch 24 Sense Ch 11 Mutliple channel operation:...
Page 84 Close/Open Switching Module Channels 2-29 Open all channels. For most switching modules, channels remain closed after the Model 2701 is turned off. Therefore, it is good safe practice to open all channels at the start and end of the test. Front panel operation: Press OPEN >...
Page 85: Identifying Installed Modules And Viewing Closed Channels
If a Model 7700, 7701, 7702, 7703, 7705, 7708, or 7709 switching module is removed while the Model 2701 is on, the instrument will operate as if the module is installed. That is, the Model 2701 will operate as if the pseudocard is installed.
Page 86 Channels 101 and 111 are the paired channels for the 4-wire measurement. Channel 123 is the 4-pole relay setting, and channels 124 and 125 connect input and sense to the DMM of the Model 2701 (Figure 2-2). NOTE Some switching modules have analog outputs, digital inputs, and/or digital outputs.
Page 87: Switching Module Queries (Remote Operation)
For remote operation, the *OPT? command can be used to determine which switching modules (or pseudocards) are installed in the Model 2701. For example, assume a Model 7700 is installed in slot 1 and the other slot is empty. The following message is the...
Page 88 Close/Open Switching Module Channels 2-33 SYSTem:CARD commands There is a series of SYSTem:CARD commands that can be used to acquire the following information about a switching module installed in the Model 2701: • Return the serial number and firmware revision. •...
Page 89: Relay Closure Count
Model 2701 User’s Manual Relay closure count The Model 2701 keeps an internal count of the number of times each module relay has been closed. The total number of relay closures are stored in EEPROM on the card. This count will help you determine if and when any relays require replacement (see module contact life specifications).
Page 90: Reading Relay Closure Count
NOTE If the Model 2701 is turned off before the updated count is written to EEPROM, the relay counts will be lost. It is good practice to add the ROUT:CLOS:COUN? <clist>...
Page 91: Model 7700 Switching Module
When the Model 2701 is on the DCV, ACV, Ω2, CONT, Ω4, FREQ, PERIOD, or TEMP function, channels 1 through 20 are available. When on a current function (DCI or ACI), channels 21 and 22 are the only available channels.
Page 92: Schematic Diagram
There are two backplane relays (channels 24 and 25) to connect the input channel(s) to the backplane of the Model 2701. With a 2-wire function (except amps) selected, channel 25 will close, and with a 4-wire function selected, both channels 24 and 25 will close.
Page 93 2-38 Close/Open Switching Module Channels Model 2701 User’s Manual Figure 2-12 Model 7700 simplified schematic Input Sense HI Cold Junction Ref x3 Channel 1 Channel 25 (See Note) (Channels 2–9) Backplane Isolation Channel 10 Input Channel 23 2-Pole (Open) Channel 24...
Page 94: Basic Dmm Operation
Basic DMM Operation • DMM measurement capabilities — Summarizes the measurement capabilities of the Model 2701 and covers maximum signal levels for switching modules. • High energy circuit safety precautions — Provides safety information when performing measurements in high energy circuits.
Page 95: Dmm Measurement Capabilities
Accuracy specifications for all measurement functions and the Model 7700 switching module are provided in Appendix A. NOTE For remote operations, you can use the internal web page of the Model 2701 to send commands, queries, and take readings. See “Internal web page” in Section 10 for details.
Page 96: High Energy Circuit Safety Precautions
As described in the International Electrotechnical Commission (IEC) Standard IEC 664, the Model 2701 measurement inputs are measurement Category I and signal lines must not be directly connected to AC mains. When making measurements in high energy circuits, use test leads that meet the following requirements: •...
Page 97: Performance Considerations
3 meters. Warm-up After the Model 2701 is turned on, it must be allowed to warm up for at least two hours to allow the internal temperature to stabilize. If the instrument has been exposed to extreme temperatures, allow extra warm-up time.
Page 98: Lsync (Line Cycle Synchronization)
Model 2701 User’s Manual Basic DMM Operation LSYNC (line cycle synchronization) Synchronizing A/D conversions with the frequency of the power line increases common mode and normal mode noise rejection. When line cycle synchronization is enabled, the measurement is initiated at the first positive-going zero crossing of the power line cycle after the trigger.
Page 99: Remote Programming - Autozero And Lsync
Basic DMM Operation Model 2701 User’s Manual Remote programming — autozero and LSYNC Autozero and LSYNC commands The commands to control autozero and line synchronization are listed in Table 3-1. Table 3-1 Autozero and LSYNC commands Commands Description Default Autozero command* SYSTem:AZERo[:STATe] ...
Page 100: Channel List Parameter ()
Basic DMM Operation Channel list parameter (<clist>) Channels of one or more switching modules installed in the Model 2701 can be scanned. Each scan channel can have its own unique setup. For example, a channel could be set to measure DCV on the 10V range, while another channel can be set to measure ACV on the 1V range.
Page 101: Voltage Measurements (Dcv And Acv)
Basic DMM Operation Model 2701 User’s Manual Voltage measurements (DCV and ACV) The Model 2701 can make DCV measurements from 0.1µV to 1000V and ACV measurements from 0.1µV to 750V RMS, 1000V peak. DCV input resistance: 100V and 1000V ranges: 10MΩ...
Page 102 Model 2701 User’s Manual Basic DMM Operation Figure 3-2 DCV and ACV connections using front panel inputs Model 2701 SENSE INPUT Ω4 WIRE Voltage 350V 1000V PEAK PEAK Source 500V PEAK INPUTS FRONT/REAR 3A 250V AMPS CAT I Input Resistance = 10MΩ on 1000V and 100V ranges;...
Page 103 3-10 Basic DMM Operation Model 2701 User’s Manual Model 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3-3. For basic DCV and ACV measurements (Figure 3-3A and B), channels 1 through 20 can be used.
Page 104: Volts Measurement Procedure
Model 2701 User’s Manual Basic DMM Operation 3-11 Volts measurement procedure NOTE Make sure the INPUTS switch is in the correct position. To use front panel inputs, it must be in the “F” (out) position. For switching modules, it must be in the “R”...
Page 105: Ac Voltage Measurements And Crest Factor
(CF) for various waveforms are shown in Figure 3-4 and Figure 3-5. The Model 2701 is an AC-coupled RMS meter. For an AC waveform with DC content, the DC component is removed before the RMS is calculated. This affects the crest factor in that the peak value of the waveform is different for a DC coupled waveform and an AC coupled waveform.
Page 106 Model 2701 User’s Manual Basic DMM Operation 3-13 Figure 3-4 ACV measurements – sine waves Sine Crest Factor: AC coupled RMS: CF = Half-Wave Rectified Sine RMS: CF = /π where; D (duty cycle) = AC coupled RMS: /π) CF = π...
Page 107 3-14 Basic DMM Operation Model 2701 User’s Manual Figure 3-5 ACV measurements – square, pulse, and sawtooth waves Square AC coupled RMS: Crest factor: CF = 1 Rectified square AC coupled RMS: CF = 2 Pulse AC coupled RMS: D(1-D)
Page 108: Low Level Considerations
Therefore, to minimize AC interference, the circuit should be shielded with the shield connected to the Model 2701 input low (particularly for low level sources). Improper shielding can cause the Model 2701 to behave in one or more of the following ways: •...
Page 109 The REL control can be used to null out constant offset voltages. AC voltage offset The Model 2701, at 5½ digits resolution, will typically display 100 counts of offset on AC volts with the input shorted. This offset is caused by the offset of the TRMS converter.
Page 110: Current Measurements (Dci And Aci)
Basic DMM Operation 3-17 Current measurements (DCI and ACI) The Model 2701 can make DCI measurements from 10nA to 3A and ACI measurements from 1µA to 3A RMS. NOTE See the previous discussion about crest factor in “Voltage measurements (DCV and ACV),”...
Page 111: Amps Measurement Procedure
3-18 Basic DMM Operation Model 2701 User’s Manual Model 7700 switching module Connections for the Model 7700 switching module are shown in Figure 3-7. Note that only channels 21 and 22 can be used for current measurements. Figure 3-7 DCI and ACI connections using Model 7700 switching module...
Page 112 Install the new fuse by reversing the procedure above. NOTE For the Model 7700 switching module and other similar modules that support the amps function, there are solder mount amps fuses. See the Model 2701 Service Manual for fuse replacement information.
Page 113: Resistance Measurements (Ω2 And Ω4)
Model 2701 User’s Manual Resistance measurements (Ω2 and Ω4) The Model 2701 has seven ohms ranges to measure resistance from 100µΩ to 120MΩ . Available measurement ranges include 100Ω , 1kΩ , 10kΩ , 100kΩ , 1MΩ , 10MΩ , and 100MΩ .
Page 114 Model 2701 User’s Manual Basic DMM Operation 3-21 Figure 3-8 Ω Ω 2 and 4 connections for front panel inputs Model 2701 Shielded Optional Shield SENSE Cable INPUT Ω4 WIRE 350V 1000V PEAK PEAK 500V Resistance PEAK INPUTS Under Test...
Page 115 3-22 Basic DMM Operation Model 2701 User’s Manual Model 7700 switching module Connections for the switching module are shown in Figure 3-9. As shown in Figure 3-9A, each of the 20 channels can be used to perform Ω2 measurements. For Ω4 measurements, a channel pair is used for each 4-wire measurement as shown in Figure 3-9B.
Page 116: Standard Resistance Measurements
Model 2701 User’s Manual Basic DMM Operation 3-23 Cable leakage For high resistance measurements in a high humidity environment, use Teflon™ insulated cables to minimize errors due to cable leakage. Standard resistance measurements NOTE Make sure the INPUTS switch is in the correct position. To use front panel inputs, it must be in the “F”...
Page 117: Offset-Compensated Ohms
D-2 for details. It includes a flowchart showing where in the processing sequence that the OCOMP operation is performed. For a normal resistance measurement, the Model 2701 sources a current (I) and measures the voltage (V). The resistance (R) is then calculated (R=V/I) and the reading is displayed.
Page 118: Measurement Methods
4 is again selected, offset-compensated ohms will be enabled. Measurement methods The Model 2701 uses two methods to measure resistance: • Constant-current source method (100Ω through 1MΩ ranges) – Sources a constant- current to the DUT. Voltage is measured by the Model 2701and resistance is then calculated (R = V/I).
Page 119 Basic DMM Operation Model 2701 User’s Manual Constant-current source method For the 100Ω to 1MΩ ranges, the Model 2701 uses the constant-current method to measure resistance. The Model 2701 sources a constant current (I ) to the DUT and measures...
Page 120 Model 2701 User’s Manual Basic DMM Operation 3-27 Figure 3-10 Constant-current method to measure ohms (100Ω to 1MΩ ranges) Ω Ω Ω A) 2-wire ohms ( 2) measurements (100 through 1M ranges) 2701 Input Hi MEAS SOUR MEAS SOUR Input Lo Ω...
Page 121 Since matched input leads are used, the voltage drop for the two test leads are 2 x V LEAD Therefore; V - 2(V MEAS LEAD The Model 2701 still uses Eq. 2 to calculate resistance, but it uses V in place of . This ratiometric method cancels the effects of input test lead resistance. MEAS...
Page 122 Model 2701 User’s Manual Basic DMM Operation 3-29 Figure 3-11 Ratiometric method to measure ohms (10MΩ and 100MΩ ranges) Ω2 Ω Ω A) 2-wire ohms ( ) measurements (10M and 100M Ω2 Function ranges) Eq. 1: 2701 Input Hi SOUR...
Page 123 120Ω will be displayed. Above 120Ω , the “OVRFLW” message is displayed. The Model 2701 will also display the “OVRFLW” message if a test lead is open during an ohms measurement. A hardware (H/W) detection circuit or software (S/W) detection is used to detect an open input lead.
Page 124 Model 2701 User’s Manual Basic DMM Operation 3-31 Figure 3-12 Open ohms test lead detection A) Normal 4-wire ohms measurement 2701 Sense HI 100mV S/W Detection Input HI H/W Detection 100mV S/W Detection Ω 100.000 I-Source 100Ω 2701 Reading Input Lo (100Ω...
Page 125: 4-Wire Common-Side (Csid) Ohms Measurements (7701 Module)
3-32 Basic DMM Operation Model 2701 User’s Manual 10MΩ and 100MΩ ranges – Open sense lead detection for the 10MΩ and 100MΩ detection is slightly different and is shown in Figure 3-13. Detection is performed at Sense Lo only. Sense Hi is not used. It does not need to be connected to the DUT. When the Sense Lo lead opens, the Sense Lo terminal will drift to -15mV and trip the “OVRFLOW”...
Page 126: Temperature Measurements
(packing list) supplied with the module. Temperature measurements The Model 2701 can measure temperature using thermocouples, thermistors, and 4-wire RTDs. When deciding which temperature sensor to use, keep in mind that the thermocouple is the most versatile, the thermistor is the most sensitive, and the 4-wire RTD is the most stable.
Page 127 Basic DMM Operation Model 2701 User’s Manual When you connect a thermocouple directly to the input of the Model 2701, at least one of those connections will be a junction made up of two dissimilar metals. Hence, another voltage is introduced and is algebraically added to the thermocouple voltage. The result will be an erroneous temperature measurement.
Page 128 DMM. If an intermittent open occurs in the thermocouple circuit, the capacitance could cause an erroneous on-scale reading. The Model 2701 has an open thermocouple detection circuit. When enabled, a 10µA pulse of current is applied to the thermocouple before the start of each temperature measurement.
Page 129: Thermistors
Curve fitting constants are used in the equation to calculate thermistor temperature. The thermistor manufacturer’s specified curve fitting constants may not be exactly the same as the ones used by the Model 2701.“Thermistor equation,” page F-6, provides the equation and the constants used by the Model 2701.
Page 130: 4-Wire Rtds
The RTD has a metal construction (typically platinum). The resistance of the RTD changes with changes in temperature. The Model 2701 measures the resistance and calculates the temperature reading. When using default RTD parameters, the resistance of the RTD will be 100Ω at 0°C.
Page 131: Connections
An ice bath, as shown in Figure 3-14A, serves as an excellent cold junction since it is relatively easy to hold the temperature to 0°C. Notice that copper wires are used to connect the thermocouple to the Model 2701 input. NOTE The positive lead of the type T thermocouple is made of copper.
Page 132 Model 2701 User’s Manual Basic DMM Operation 3-39 Figure 3-14 Thermocouple connections Model 2701 A. Simulated reference junction (front panel inputs) B. Simulated reference junction (Model 7700) C. Internal reference junction (Model 7700) D. Channel average calculation, internal reference junction (Model 7700)
Page 133 3-40 Basic DMM Operation Model 2701 User’s Manual Table 3-2 Color codes — thermocouple wires T/C type Positive (+) Negative (-) T/C type Positive (+) Negative (-) J U.S. White E U.S. Purple British Yellow Blue British Brown Blue Blue...
Page 134 B. Model 7700 switching module 4-wire RTD connections Shown in Figure 3-16 are 4-wire RTD connections to the Model 2701. For the Model 7700 switching module, paired channels are used to perform the 4-wire measurement. The two input leads of the RTD are connected to a primary channel (1 through 10), while the two sense leads are connected to its paired channel (11 through 20).
Page 135: Temperature Measurement Configuration
3-42 Basic DMM Operation Model 2701 User’s Manual Temperature measurement configuration The Model 2701 is configured to measure temperature from the temperature measurement configuration menu. Use the following general rules to navigate through the menu structure: • Press SHIFT and then SENSOR to enter the menu structure.
Page 136 Model 2701 User’s Manual Basic DMM Operation 3-43 Table 3-3 Thermocouple temperature measurement configuration Step Menu structure Description UNITS: C, F, or K Select temperature measurement units (°C, °F, or K). SENS: TCOUPLE Select the thermocouple transducer. TYPE: J, K, T, E, R, S, B, or N Select thermocouple type.
Page 137 3-44 Basic DMM Operation Model 2701 User’s Manual 4-wire RTD temperature measurement configuration The Alpha, Beta, Delta, and Ω at 0°C parameters for the five basic RTD types are provided in Table 3-5. Note that these parameters can be modified using remote programming.
Page 138: Temperature Measurement Procedure
Model 2701 User’s Manual Basic DMM Operation 3-45 Temperature measurement procedure NOTE Make sure the INPUTS switch is in the correct position. To use front panel inputs, it must be in the “F” (out) position. For switching modules, it must be in the “R”...
Page 139: Frequency And Period Measurements
Gate time The gate time is the amount of time the Model 2701 uses to sample frequency or period readings. Use the RATE key to set the gate time; SLOW sets the gate time to 1.0 sec, MED sets it to 0.1 sec, and FAST sets it to 0.01 sec.
Page 140: Connections
Model 2701 User’s Manual Basic DMM Operation 3-47 Connections NOTE When using the front panel inputs, the INPUTS switch must be in the “F” (out) position. For switching modules, it must be in the “R” (in) position. Front panel input When using the front panel input terminals, connect the test leads to the INPUT HI and LO terminals as shown in Figure 3-17.
Page 141: Frequency And Period Measurement Procedure
3-48 Basic DMM Operation Model 2701 User’s Manual Frequency and period measurement procedure NOTE Make sure the INPUTS switch is in the correct position. To use front panel inputs, it must be in the “F” (out) position. For switching modules, it must be in the “R”...
Page 142: Connections
Model 2701 User’s Manual Basic DMM Operation 3-49 will not beep and either display the resistance reading or the message “OPEN”. If the reading is below 1100Ω , it will be displayed. If the reading is 1100Ω or above, “OPEN” will instead be displayed.
Page 143: Continuity Testing Procedure
3-50 Basic DMM Operation Model 2701 User’s Manual Continuity testing procedure NOTE Make sure the INPUTS switch is in the correct position. To use front panel inputs, it must be in the “F” (out) position. For switching modules, it must be in the “R”...
Page 144: Remote Programming For Basic Measurements
Model 2701 User’s Manual Basic DMM Operation 3-51 Remote programming for basic measurements Basic measurement commands NOTE When measurements are performed, the readings are fed to other enabled processing operations. Appendix D explains “Data flow (remote operation)” and the commands used to return the various processed readings.
Page 145 3-52 Basic DMM Operation Model 2701 User’s Manual Table 3-7 (continued) Basic measurement commands Commands Description Default Ref TEMP function [SENSe[1]] Optional root command. :TEMPerature:TRANsducer <name> Select temperature transducer; <name> = [, <clist>] TCouple, FRTD, or THERmistor. :TEMPerature:TCouple[:TYPE] <type> Select T/C type; <type> = J, K, T, E, [, <clist>]...
Page 146 Model 2701 User’s Manual Basic DMM Operation 3-53 Table 3-7 (continued) Basic measurement commands Commands Description Default Ref PERIOD function :PERiod:THReshold:VOLTage:RANGe Select threshold voltage range; <n> [, <clist>] <n> = 0 to 1010. :PERiod:APERture <n> [, <clist>] Set gate time for PERIOD measurements in secs;...
Page 147 3-54 Basic DMM Operation Model 2701 User’s Manual Reference FUNCtion <name> [, <clist>] Note that the <name> parameters in the table are enclosed in single quotes (‘ ’). However, double quotes (“ ”) can instead be used. For example: FUNC ‘VOLT:AC’ = FUNC “VOLT:AC”...
Page 148 Model 2701 User’s Manual Basic DMM Operation 3-55 TEMPerature:TCouple:RJUNction:SIMulated <n> [, <clist>] The units for the simulated reference temperature depend on the present temperature measurement units as set by UNIT:TEMPerature (see Ref h). NOTE The following command can instead be used to set the simulated reference temperature: TEMPerature:RJUNction:SIMulated <n>...
Page 149 3-56 Basic DMM Operation Model 2701 User’s Manual DATA[:LATest]? DATA:FRESh? These commands do not trigger a reading. They simply return the last reading string. The reading reflects what is applied to the input. While the instrument is performing measurements, you can use these commands to return the last reading.
Page 150: Basic Measurement Programming Examples
3-57 Basic measurement programming examples Example #1 — continuous triggering The following command sequence places the Model 2701 in a continuous trigger mode to measure ACV. Whenever DATA? is sent the last measured reading will be sent to the computer.
Page 151: Measurement Queries
3-58 Basic DMM Operation Model 2701 User’s Manual Example #4 — Scan configuration (Model 7700) The following commands configure scan channels 101, 102, and 121 of a Model 7700 installed in slot 1. When channel 101 is scanned, DCV will be selected. When channel 102 is scanned, Ω2 will be selected.
Page 152: Read
Model 2701 User’s Manual Basic DMM Operation 3-59 Where appropriate Since this query does not trigger a reading and can give duplicate results, there are not many cases where this command should be used. The “:DATA:FRESh?” query (see page 3-47) is often a better choice. If this query is used, the following conditions should be met: •...
Page 153: Measure[:]
3-60 Basic DMM Operation Model 2701 User’s Manual :MEASure[:<function>]? What it does This query will reconfigure the instrument to the function specified in the query, set the trigger source for immediate, set the trigger count to 1, and configure the measurement parameters to *RST defaults.
Page 154: [:Sense[1]]:Data[:Latest]
Model 2701 User’s Manual Basic DMM Operation 3-61 [:SENSe[1]]:DATA[:LATest]? What it does This query will return the last reading the instrument had, regardless of what may have invalidated that reading, such as changing ranges or functions. Limitations This query is fully capable of returning meaningless, old data.
Page 155 3-62 Basic DMM Operation Model 2701 User’s Manual One-shot reading, external trigger, auto delay enabled *RST :TRIGger:SOURce EXTernal // Note: Auto trigger delay only takes effect with :TRIGger:DELay:AUTO ON // trigger source set for BUS or EXTernal. :SENSe:FUNCtion ‘VOLTage:DC’ :SENSe:VOLTage:DC:RANGe:AUTO ON...
Page 156: Range, Digits, Rate, Bandwidth, And Filter
Range, Digits, Rate, Bandwidth, and Filter • Range — Provides details on measurement range selection. Includes the commands for remote programming. • Digits — Provides details on selecting display resolution. Includes the commands for remote programming. • Rate and bandwidth — Provides details on integration rate and bandwidth (for AC measurements).
Page 157: Range
Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Range The range setting is “remembered” by each measurement function. When you select a function, the instrument will return to the last range setting for that function. Measurement ranges and maximum readings The selected range affects both accuracy of the measurement as well as the maximum level that can be measured.
Page 158: Manual Ranging
Auto ranging should not be used when optimum speed is required. Note that the AUTO key has no effect on temperature (TEMP). Up-ranging occurs at 120% of range. The Model 2701 will down-range when the reading is <10% of nominal range.
Page 159: Remote Programming - Range
Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Remote programming — range Range commands The commands to set range are listed in Table 4-2. Additional information on these commands follow the table. NOTE Query commands and some optional command words are not included in Table 4-2.
Page 160 The range is selected by specifying the expected reading as an absolute value using the <n> parameter for the appropriate :RANGe command. The Model 2701 will then go to the most sensitive range for that expected reading. For example, if you expect a reading of approximately 3V, let the parameter (<n>) equal 3 to select the 10V range.
Page 161: Digits
Model 2701 User’s Manual Digits The DIGITS key sets display resolution for the Model 2701 from 3½ to 6½ digits. From the front panel, setting digits for one function affects all the other functions. For example if you set DCV for 3½ digits, the other functions will also set to 3½ digits. For remote pro- gramming, each mainframe input function can have its own unique digits setting.
Page 162 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter Table 4-3 Digits commands Commands* Description Default [SENSe[1]] Optional root command. :VOLTage[:DC]:DIGits <n> [, <clist>] Set # of digits for DCV; <n> = 4 to 7. :VOLTage:AC:DIGits <n> [, <clist>] Set # of digits for ACV;...
Page 163: Rate And Bandwidth
The Model 2701 has a parabola-like shape for its speed vs. noise characteristics and is shown in Figure 4-1. The Model 2701 is optimized for the 1 PLC to 5 PLC reading rate. At these rates (lowest noise region in graph), the Model 2701 will make corrections for its own internal drift and still be fast enough to settle a step response <100ms.
Page 164 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter The front panel RATE key settings for all but the AC functions are explained as follow: • FAST sets integration time to 0.1 PLC. Use FAST if speed is of primary importance (at the expense of increased reading noise and fewer usable digits).
Page 165: Bandwidth
SLOW) turns on. NOTE The Model 2701 uses internal references to calculate an accurate and stable reading. When the NPLC setting is changed, each reference must be updated to the new NPLC setting before a reading is generated. Therefore, frequent NPLC setting changes can result in slower measurement speed.
Page 166: Remote Programming - Rate And Bandwidth
Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-11 Remote programming — rate and bandwidth Rate and bandwidth commands The commands to set the integration rate and bandwidth are listed in Table 4-5. Additional information on these commands follows the table.
Page 167 4-12 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Table 4-5 (continued) Rate and bandwidth commands 1, 6 Commands Description Default Bandwidth commands [SENSe[1]] :VOLTage:AC:DETector:BANDwidth Set AC bandwidth for ACV in Hertz; <NRf> = <NRf> [, <clist>] 3 to 3e5.
Page 168 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-13 To set bandwidth, simply specify (approximately) the frequency of the input signal. The instrument will automatically set the bandwidth as follows: <NRf> = 3 to 29 3Hz to 300kHz...
Page 169: Filter
4-14 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Filter The digital filter is used to stabilize noisy measurements. The displayed, stored, or transmitted reading is a windowed-average of a number of reading conversions (from 1 to 100).
Page 170 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-15 NOTE While the filter processes readings, the FILT annunciator blinks. Readings that are being displayed while the FILT annunciator blinks are not final filtered readings. When the FILT annunciator stops blinking, the filter has settled.
Page 171 4-16 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual readings). A reading conversion outside the plus or minus noise window fills the filter stack immediately. If the noise does not exceed the selected window, the reading is based on the average of the reading conversions.
Page 172 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-17 Figure 4-3 Filter window +1% of range Voltage Windows Violation -1% of range +1% of range -1% of range Integration Time Conversions: Filter configuration: Type = Moving Count = 5...
Page 173 4-18 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Filter control and configuration The FILTER key toggles the state of the Filter. When the Filter is enabled, the FILT annunciator is on. The FILT annunciator will flash when the filter is not settled. When disabled, the FILT annunciator is off.
Page 174 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-19 Figure 4-4 Filter configuration flow chart SHIFT TYPE 0.01% 0.1% WINDOW NONE 001 to 100 RDGS REPEAT TYPE MOVNG AV Scanning The moving filter cannot be used when scanning. A scan channel cannot be configured to use the moving filter.
Page 175: Remote Programming - Filter
4-20 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Remote programming — filter Filter commands The filter commands are listed in Table 4-6. Additional information on these commands follow the table. NOTE Query commands are not included in Table 4-6. All commands for the SENSe subsystem are provided in Table 15-5.
Page 176 Model 2701 User’s Manual Range, Digits, Rate, Bandwidth, and Filter 4-21 Table 4-6 (continued) Filter commands 1, 4 Commands Description Default Ω2 filter commands [SENSe[1]] Optional root command. :RESistance:AVERage:TCONtrol <name> Select filter type; <name> = MOVing or (Note 2) REPeat.
Page 177 4-22 Range, Digits, Rate, Bandwidth, and Filter Model 2701 User’s Manual Filter programming examples Example #1 — The following command sequence configures filtering for the DCI function: NOTE The following example can be run from the KE2700 Instrument Driver using the example named “MAFilter”...
Page 178: Relative, Math, Ratio, Channel Average, And Db
Relative, Math, Ratio, Channel Average, and dB • Relative — Explains how to null an offset or establish a baseline value. Includes the commands for remote programming. • Math — Covers the three basic math operations: mX+b, percent, and reciprocal (1/X).
Page 179: Relative
Selecting a range that cannot accommodate the rel value does not cause an overflow condition, but it also does not increase the maximum allowable input for that range. For example, on the 10V range, the Model 2701 still overflows for a 12V input. NOTE The various instrument operations, including Relative, are performed on the input signal in a sequential manner.
Page 180 Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB If using a switching module, use the key to select (close) the input channel. If using the front panel inputs (FRONT inputs selected), it does not matter if a switching channel is closed.
Page 181: Remote Programming - Rel
Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Remote programming — rel Rel commands The rel commands to set range are listed in Table 5-1. Additional information on these commands follow the table. NOTE Query commands are not included in Table 5-1. All commands for the SENSe subsystem are provided in Table 15-5.
Page 182 Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB Table 5-1 (continued) Rel commands Commands Description Default Rel commands for Ω2 [SENSe[1]] Optional root command. :RESistance:REFerence <n> [, <clist>] Specify rel value; <n> = 0 to 120e6 (Ω). :RESistance:REFerence:STATe [, <clist>] Enable/disable rel;...
Page 183 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual “Pressing REL” using rel commands When the front panel REL key is pressed, the displayed reading is used as the rel value. Subsequent readings are then the result of the actual input value and the rel value.
Page 184: Math
' Enable rel. Math The Model 2701 has three built-in math calculations that are accessed from the MATH menu: mX+b, percent, and reciprocal (1/X). Figure 5-1 shows the MATH menu tree. Note that the settings shown in the menu tree are the factory defaults.
Page 185: Mx+B
Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual mX+b This math operation lets you manipulate normal display readings (X) mathematically according to the following calculation. Y = mX + b where: X is the normal display reading. m and b are the user-entered constants for scale factor and offset.
Page 186: Percent
Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB mX+b rel The mX+b function can be used to manually establish a rel value. To do this, set the scale factor (m) to 1 and set the offset (b) to the rel value. Each subsequent reading will be the difference between the actual input and the rel value (offset).
Page 187: Reciprocal (1/X)
5-10 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Reciprocal (1/X) The reciprocal of a reading is displayed when the reciprocal (1/X) math function is enabled: Reciprocal = 1/X where: X is the normal input reading The displayed units designator for reciprocal readings is “R.” This units designator cannot be changed.
Page 188: Basic Operation
Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB 5-11 Basic operation NOTE If using switching module inputs, make sure the front panel INPUTS switch is set to the REAR position (in). If using the front panel inputs, the switch must be in the FRONT position (out).
Page 189: Remote Programming - Math
5-12 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Remote programming — math Math commands NOTE When measurements are performed, the readings are fed to other enabled processing operations, including Math. Appendix D explains “Data flow (remote operation),” page D-7 and the commands used to return Math results.
Page 190 Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB 5-13 Setting mX+b units The <char> parameter for CALCulate:KMATh:MUNits must be one character enclosed in single or double quotes. It can be any letter of the alphabet, the degrees symbol (°), or the ohms symbol (Ω).
Page 191 5-14 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Math programming examples Example #1 — The following command sequence performs the mX+b calculation for channels 101 and 102 of the Model 7700. NOTE The following example can be run from the KE2700 Instrument Driver using the example named “Linear”...
Page 192: Ratio And Channel Average
5-15 Ratio and channel average With a switching module installed in the Model 2701, the ratio or average of two channels can be calculated and displayed. The ratio calculation can be done on the DCV function and the channel average calculation can be done on the DCV and TEMP (thermocouples only) functions.
Page 193: Basic Operation
5-16 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Basic operation NOTE Make sure the INPUTS switch is set to the REAR position (in). Select and configure (range, filter, rel, etc.) a valid measurement function. For ratio, the only valid function is DCV. For channel average, the only valid functions are DCV and TEMP (TCs only).
Page 194 Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB 5-17 Scanning Ratio and channel average can be used in an advanced scan. The 2-channel scan for the calculation is performed for every primary channel that is scanned. For example, assume the Model 7700 is installed in slot 1 and is configured to perform the ratio calculation for 10 channels.
Page 195: Remote Programming - Ratio And Channel Average
5-18 Rel, Math, Ratio, Channel Average, dB Model 2701 User’s Manual Remote programming — ratio and channel average Ratio and channel average commands The ratio and channel average are listed in Table 5-3. Details on these commands follow the table.
Page 196 Model 2701 User’s Manual Rel, Math, Ratio, Channel Average, dB 5-19 Ratio and channel average programming examples Example #1 — The following command sequence performs the ratio calculation using pri- mary channel 102 of the Model 7700. NOTE The following example can be run from the KE2700 Instrument Driver using the example named “Ratio1”...
Page 197: Remote Programming - Db
= 1µV and V = 1000V. dB configuration Remote programming must be used to configure the Model 2701 for dB measurements. It cannot be configured from the front panel. Scanning Typically a scan using dB is configured and run using remote programming. However, once dB is selected using remote programming, a simple dB scan can be configured and run from the front panel.
Page 198 101 is set for the ACV function. Programming examples — dB Example #1 — The following command sequence configures the Model 2701 to perform DCV dB measurements. A 1V input will be measured as 0dB.
Page 199: Buffer
Buffer • Buffer overview — Summarizes basic buffer (data store) capabilities. • Front panel buffer — Explains how to store and recall readings. Discusses the various statistics available on buffer data including minimum and maximum values, average (mean), standard deviation, and peak-to-peak values. •...
Page 200: Buffer Overview
Model 2701 User’s Manual Buffer overview The Model 2701 has a data store (buffer) to store from 2 to 450,000 readings. The instrument stores the readings that are displayed during the storage process. Each timestamped reading includes the buffer location number and a timestamp.
Page 201 Buffer NOTE If the buffer is empty when the Model 2701 is turned off, buffer auto clear will enable when it is turned back on. If the buffer is not empty, the instrument will power up to the last auto clear set- ting.
Page 202: Timestamps
Therefore, the timestamp for the 11th reading (#10) is one hour (3600 seconds). When the Model 2701 is turned off, the relative timestamp resets to 0 sec when the instrument is turned back on. If you have readings stored in the buffer and auto clear is disabled when the unit is turned off, subsequent stored readings will be appended to the old group of readings.
Page 203: Storing Readings
ENTER. Storing readings Perform the following steps to store readings: Set up the Model 2701 for the desired configuration. Press the STORE key. Use the , , and keys to specify the number of readings to store in the buffer (2 to 450000).
Page 204: Recalling Readings
Buffer Model 2701 User’s Manual Recalling readings Readings stored in the buffer are displayed by pressing the RECALL key. The readings are positioned at the left side of the display, while the buffer location number (reading number) and timestamps are positioned at the right side.
Page 205: Buffer Statistics
Model 2701 User’s Manual Buffer Figure 6-2 Recalling buffer data — real-time clock timestamp Reading Value Time Date Reading Value Time Date Reading Value Time Date Reading Value Time Date Reading Value Time Date Reading Value Time Date Reading Value...
Page 206: Remote Programming - Buffer
If the standard deviation calculation is being performed on a buffer that has more than 1000 readings, the “CALCULATING” message will flash to indicate that the Model 2701 is busy. While busy with the calculation, front panel keys will not operate. It will take approximately five seconds to calculate standard deviation on 450,000 readings.
Page 207 Model 2701 User’s Manual Buffer Table 6-1 Buffer commands Command Description Default SYSTem:TIME <hr, min, sec> Set clock time in 24-hour format. SYSTem:DATE <yr, mo, day> Set clock date; yr specified as 20xx. SYSTem:TSTamp:TYPE Select timestamp; <name> = RELative or RTCLock.
Page 208 Control (on/off) buffer auto-clear TRACe:CLEar — Used to clear the buffer. Buffer readings are not lost (cleared) when the Model 2701 is turned off. When TRAC:CLE is sent while displaying stored readings, the message “BUF CLEARED” is briefly displayed and the instrument returns to the normal measurement state.
Page 209 Model 2701 User’s Manual Buffer 6-11 TRACe:POINts <NRf> Set buffer size (2 to 450000) TRACe:POINts? Query buffer size TRACe:POINts:ACTual? Query # of readings stored in buffer TRACe:POINts <NRf> – With buffer auto-clear enabled, you can set the buffer to store from 2 to 450,000 readings. A buffer size of zero or one is not valid (error -222).
Page 210 6-12 Buffer Model 2701 User’s Manual TRACe:DATA? Read buffer Use TRACE:DATA? to retrieve all readings that are stored in the buffer. You can send this command even if the instrument is still storing readings. When TRACe:DATA? is sent, it will return the readings stored up to that point in time. Subsequent TRACe:DATA? commands will not retrieve readings already returned.
Page 211 Model 2701 User’s Manual Buffer 6-13 TRACe:NOTify <NRf> Specify number of readings that will set Trace Notify bit <NRf> = 1 to 449999 Use this command to specify the number of stored readings that will set bit B6 (Trace Notify) of the measurement event register. See Section 11 for details on status structure.
Page 212 Use *OPC or *OPC? with CALC2:IMM and CALC2:IMM? when performing the standard deviation calculation on a large buffer. See Section 12 for details on *OPC and *OPC? NOTE The Model 2701 should take 5 to 6 seconds to perform standard deviation on 450,000 readings.
Page 213: Programming Example
Model 2701 User’s Manual Buffer 6-15 Programming example The following command sequence stores 20 readings in the buffer and then calculates the mean for those readings: NOTE The following example can be run from the KE2700 Instrument Driver using the example named “BufStats”...
Page 214: Scanning
Scanning • Scanning fundamentals — Explains channel assignments (slot/channel programming format), the difference between sequential and non-sequential scans, and the basic scan process. Block diagrams (known as trigger models) are provided to help explain the STEP and SCAN operations. • Scan configuration —...
Page 215: Scanning Fundamentals
Model 2701 User’s Manual Scanning fundamentals The Model 2701 can scan the channels of up to two installed Keithley switching modules. Each scan channel can have its own unique setup. Aspects of operation that can be uniquely set for each channel include function, range, rate, AC bandwidth, rel, filter, digits, math, Ω...
Page 216: Channel Assignments
Model 2701 User’s Manual Scanning Channel assignments A switching module has a certain number of channels. For example, the Model 7700 switching module has 22 channels (1 through 22). When you encounter a 1 or 2-digit channel number in this manual, the switching module channel is the point of discussion.
Page 217: Scan Process
Therefore, the reading (and annunciators) pertains to the channel and does not necessarily indicate the present state of the Model 2701. If the display is blanked (-------), the displayed channel is closed and has not been measured.
Page 218 Model 2701 User’s Manual Scanning NOTE The trigger model in Figure 7-2 also applies for bus operation. See “Remote programming — scanning,” page 7-26, for differences between front panel and remote scanning. For the following discussion, refer to Figure 7-1 for STEP operation and Figure 7-2 for SCAN operation.
Page 219 Scanning Model 2701 User’s Manual Figure 7-2 Trigger model with SCAN function Enable Scan Close First Chan in List Trigger Another Counter Scan? Event Control Detection Source Immediate External Timer Timer Manual* Output Enabled Bus* Trigger Timer Bypass Timer >...
Page 220 After the last channel in the scan list is measured, the Model 2701 outputs a trigger pulse. If programmed to again scan the channels in the scan list, the Model 2701 will wait at the control source for another trigger event. After all the scan list channels are again measured, the Model 2701 will output another trigger pulse.
Page 221 Scanning Model 2701 User’s Manual Immediate control source With immediate triggering, event detection is immediate allowing channels to be scanned. Timer control source With the timer source enabled (selected), event detection is immediately satisfied. On the initial pass through the loop, the Timer Bypass is enabled allowing operation to bypass the Timer and continue to the Delay block.
Page 222 Model 2701 User’s Manual Scanning Delays As shown in the trigger models, operation may be subjected to one or more delays before a channel is measured. NOTE As previously explained, if the timer control source is selected and its user-set interval is greater than the user-set Delay, the Timer interval will supersede the Delay period after the first pass through the loop.
Page 223 7-10 Scanning Model 2701 User’s Manual Reading count NOTE For both STEP and SCAN, the reading count specifies the number of readings to store in the buffer. STEP operation — The reading count specifies the number of channels to scan. This can be equal to, less than, or greater than the number of channels in the scan list.
Page 224: Scan Configuration
Model 2701 User’s Manual Scanning 7-11 Scan configuration A scan is configured from the scan configuration menu which is accessed by pressing SHIFT and then CONFIG. Figure 7-3 shows the basic flowchart to configure a scan. After entering the menu structure you can configure a simple scan, an advanced scan, or reset the configuration to the default setup for a simple scan.
Page 225 7-12 Scanning Model 2701 User’s Manual There are two scan configurations: simple and advanced. When you configure the simple scan, the instrument uses the present instrument setup for each channel in the scan. For the advanced scan, each channel can have its own unique setup. As explained in “Trigger models,”...
Page 226: Scan Reset
Model 2701 User’s Manual Scanning 7-13 Scan reset From the scan configuration menu, you can reset the scan configuration to the default setup for a simple scan. For the Model 7700 switching module, channels 21 and 22 are turned off (not used) and...
Page 227: Advanced Scan
7-14 Scanning Model 2701 User’s Manual If you enabled the timer, set the timer interval using the hour/minute/second for- mat. The timer can be set from 0.001 sec (00H:00M:00.001S) to 99 hrs, 99 min, 99.999 sec (99H:99M:99.999S). Note that pressing the AUTO key sets the timer to 0.001 sec.
Page 228 Model 2701 User’s Manual Scanning 7-15 Advanced scan setup notes The CHAN annunciator is on while in the scan setup menu. For some channel-specific setups, you have to configure them from a menu. For example, to set up and enable mX+B, you have to use MATH menu. While in that menu, the CHAN annunciator will flash to indicate that you are editing the mX+b math setup for that channel in the scan list.
Page 229 7-16 Scanning Model 2701 User’s Manual Advanced scan setup procedure Step 1: Select the advanced scan configuration menu Press SHIFT and then CONFIG to access the scan setup menu. Press the or key to display INT: ADVANCED and press ENTER.
Page 230 Model 2701 User’s Manual Scanning 7-17 Step 3: Enable immediate scan The present state of immediate scan (IMM SCAN) is displayed, Y (yes, which is the factory and *RST default) or N (no). With immediate scan enabled, the scan will start when you press the STEP or SCAN key.
Page 231: Setting Delay
7-18 Scanning Model 2701 User’s Manual Setting delay As shown in Figure 7-1 and Figure 7-2, a delay (auto or manual) can be set by the user. With auto delay selected, the delay period depends on function and range (Table 8-1).
Page 232 7-19 NOTE An overflow reading (“OVRFLW” message displayed) is interpreted by the Model 2701 as a positive reading, even if the input signal is negative. This could inadvertently trigger a monitor scan (see “Scan operation — Monitor scan,” page 7-35).
Page 233: Auto Channel Configuration
7-20 Scanning Model 2701 User’s Manual Auto channel configuration Auto channel configuration allows you to recall scan list setups. With auto channel configuration enabled, a closed channel assumes the scan list setup. With this feature, you can inspect the channel setups of the scan or manually scan channels. When a scan channel is disabled (not in scan list), it cannot be closed with auto channel configuration enabled.
Page 234: Saving Setup
When auto scan is enabled, the scan operation is saved in memory. If power to the Model 2701 is interrupted, the scan will resume when power is restored. With auto scan enabled, the last scan setup becomes the power-on setup. It takes precedence over the factory, *RST, or user-saved power-on setup.
Page 235: Basic Scan
7-22 Scanning Model 2701 User’s Manual Basic scan Perform the following steps to run the presently configured scan: To start the scan, press STEP or SCAN. The STEP or SCAN annunciator turns on and channels are scanned from the lowest to highest number channel. Channels that are turned off will not be scanned.
Page 236: Manual/External Trigger Scan
After the last scan is completed, the scan remains enabled (SCAN annunciator on), but the Model 2701 goes into the idle state. If you wish to repeat the scans, you will have to first take the Model 2701 out of idle. This can be done by pressing the SCAN (or TRIG) key.
Page 237: Monitor Scan (Analog Trigger)
NOTE An overflow reading (“OVRFLW” message displayed) is interpreted by the Model 2701 as a positive reading, even if the input signal is negative. This could inadvertently trigger a monitor scan. For example, assume the monitor channel is monitoring a negative input signal and the instrument is configured to trigger a monitor scan if a positive input signal is detected.
Page 238 Model 2701 User’s Manual Scanning 7-25 Press the or key to display IMM SCAN: N and press ENTER. Press the or key to enable or disable low limit 1 (LLIM1 SCAN:N/Y) and press ENTER. Press the or key to enable or disable high limit 1 (HLIM1 SCAN:N/Y) and press ENTER.
Page 239: Remote Programming - Scanning
7-26 Scanning Model 2701 User’s Manual Remote programming — scanning NOTE Scanning examples (remote programming and front panel operation) are provided at the end of this section. Trigger model The trigger model for bus operation is shown in Figure 7-2. Bus operation is similar to front panel SCAN operation, with the following significant differences: Idle —...
Page 240: Channel Setup
Model 2701 User’s Manual Scanning 7-27 Channel setup The <clist> parameter is used to set up scan channels. For example, the following examples show how to set up scan channel 101: FUNC 'VOLT', (@101) ' Set 101 for DCV. VOLT:RANG 10, (@101) ' Set 101 for 10V range.
Page 241 7-28 Scanning Model 2701 User’s Manual Table 7-1 Scanning commands Commands Description Default Ref Scan commands ROUTe:SCAN <clist> Specify list of channels to be scanned. ROUTe:SCAN? Returns list of channels to be scanned. ROUTe:SCAN:TSOurce <list> Select trigger(s) to start scan; <list> = IMMediate or HLIMit1, LLIMit1, HLIMit2, LLIMit2.
Page 242 Model 2701 User’s Manual Scanning 7-29 Table 7-1 (continued) Scanning commands Commands Description Default Ref Buffer commands TRACe:DATA? Read buffer readings. TRACe:CLEar Clear buffer. Channel list parameter: <clist> = (@SCH) where: S = Mainframe slot number (1 or 2) CH = Switching module channel number (must be 2 digits)
Page 243 7-30 Scanning Model 2701 User’s Manual NOTE Non-sequential scanning is only intended to be performed using remote programming. Unexpected results may occur if a non-sequential scan is run from the front panel. There must be at least two channels in the scan list. Creating a scan list that has only one channel will generate error -221 (settings conflict).
Page 244 Model 2701 User’s Manual Scanning 7-31 Examples: ROUT:SCAN:TSO IMM ' Start scan when it is enabled and triggered. ROUT:SCAN:TSO HLIM1,LLIM1 ' Enable high limits 1 and low limits 1. Note that any reached limit will start the scan. ROUTe:MONitor <clist> — The channel that you specify as the monitor must be a channel that is in the scan list.
Page 245: Scanning Programming Example
7-32 Scanning Model 2701 User’s Manual Scanning programming example The following program will scan 10 channels (101 through 110): NOTE The following example can be run from the KE2700 Instrument Driver using the example named “ScanChan” in Table G-1 of Appendix G.
Page 246 As shown in the operation model, when the scan is enabled, channel 101 closes and the Model 2701 waits for an external trigger. When the trigger is received, channels 101 and 102 are measured. Operation then returns to the control source where it waits for another trigger.
Page 247 7-34 Scanning Model 2701 User’s Manual Table 7-2 External trigger scan example Front panel operation Remote programming Restore defaults: Restore defaults (SHIFT SETUP > RESTORE: FACT). *RST For front panel operation, proceed to step 3. For remote programming, clear buffer and disable...
Page 248: Monitor Scan
30°C, the instrument will remain in the monitor mode. When the temperature reading reaches 30°C, the Model 2701 switches over to the scan mode. Figuratively speaking, it is as if a “finger” presses the SCAN key when the monitor detects that the average temperature is at or above 30°C.
Page 249 7-36 Scanning Model 2701 User’s Manual Figure 7-5 Monitor scan example Monitor Mode: Close Monitor Channel (101) ≥30˚C SCAN Measure TEMP Scan Mode: Close First Return to Channel Monitor Mode Measurements Open Last Chan Close Next Chan Measure...
Page 250 Model 2701 User’s Manual Scanning 7-37 Table 7-3 Monitor scan example Front panel operation Remote programming Restore defaults (SHIFT SETUP > RESTORE: FACT). SYST:PRES For front panel operation, proceed to step 3. For remote programming, clear the buffer: TRAC:CLE Configure advanced scan: SHIFT CONFIG >...
Page 251: Triggering
Reading hold — Explains the Reading Hold feature which is used to screen out readings that are not within a specified reading window. • External triggering — Explains external triggering which allows the Model 2701 to trigger and be triggered by other instruments. •...
Page 252: Trigger Model
Triggering Model 2701 User’s Manual Trigger model The flow chart in Figure 8-1 summarizes triggering as viewed from the front panel. It is called a trigger model because it is modeled after the SCPI commands used to control triggering. NOTE For scanning, the trigger model has additional control blocks, such as a Timer.
Page 253: Control Source And Event Detection
An input trigger via the Trigger Link line EXT TRIG is received. • The front panel TRIG key is pressed. (The Model 2701 must be taken out of remote before it will respond to the TRIG key. Use the LOCAL key or send SYSTem:LOCal over the Ethernet or RS-232.)
Page 254 Triggering Model 2701 User’s Manual Scanning — When scanning, the nominal delay will be long enough to allow each switch- ing module channel relay to settle before making the measurement. When scanning, the auto delay times in Table 8-1 are valid for all control sources.
Page 255: Device Action
Model 2701 User’s Manual Triggering Device action The primary device action is a measurement. However, the device action block could include the following additional actions (Figure 8-2): Figure 8-2 Device action To Output Trigger From Delay Block Block of Figure 8-1...
Page 256: Reading Hold (Autosettle)
Press DCV to measure DC voltage. Apply the test signal to the input of the Model 2701. Once the signal becomes sta- ble enough to satisfy the hold condition, the reading is released and the beeper sounds (if enabled).
Page 257: External Triggering
TRIG key to trigger a single reading. Pressing the EX TRIG key again toggles back to continuous triggers. The Model 2701 uses two lines of the TRIG LINK rear panel connector as External Trigger (EXT TRIG) input and Voltmeter Complete (VMC) output. The EXT TRIG line allows the Model 2701 to be triggered by other instruments.
Page 258: Digital I/O
Digital I/O Pin 6 (Ext Trig) of the Digital I/O can also be used as the external trigger input for the Model 2701. Line 2 of the TRIG LINK is physically connected to pin 6 of the Digital I/O connector.
Page 259 Model 2701 User’s Manual Triggering Figure 8-4 Trigger link input pulse specifications (EXT TRIG) Triggers on Leading Edge TTL High (2V-5V) TTL Low (≤0.8V) 2μs Minimum...
Page 260: Voltmeter Complete
The VMC output provides a TTL-compatible output pulse that can be used to trigger other instruments. The specifications for this trigger pulse are shown in Figure 8-5. Typically, you would want the Model 2701 to output a trigger after the settling time of each measurement.
Page 261: External Triggering Example
The Trigger Link connections for this test system are shown in Figure 8-7. Trigger Link of the Model 2701 is connected to Trigger Link (either IN or OUT) of the Model 7002. Note that with the default trigger settings on the Model 7002, line #1 is an input and line #2 is an output.
Page 262 8-12 Triggering Model 2701 User’s Manual Model 7002 Factory defaults restored Scan list = 1!1-1!400 Number of scans = 1 Channel spacing = TrigLink Figure 8-7 Trigger link connections Model 7002 Link/Act 100bT DIGITAL I/O TRIGER ETHERNET RS-232 (EXT. TRIG.)
Page 263 Scanned Channels Pressing EX TRIG on the Model 2701 places it at point A in the flowchart, where it is waiting for an external trigger. Pressing STEP on the Model 7002 takes it out of the idle state and places operation at point B in the flow chart.
Page 264: External Triggering With Bnc Connections
(point F) and then loops back to point A where it waits for another input trigger. The trigger applied to the Model 7002 from the Model 2701 closes the next channel in the scan. This triggers the Model 2701 to measure the next DUT. The process continues until all 400 channels are scanned, measured, and stored in the buffer.
Page 265 Model 2701 User’s Manual Triggering 8-15 Figure 8-9 DIN to BNC trigger cable Model 220 Current Source Link/Act 100bT RS-232 DIGITAL I/O TRIGGER ETHERNET (EXT. TRIG.) LINK 10/100 BaseT ~LINE RATING 50, 60, 400Hz 80VA MAX Model 2701...
Page 266: Remote Programming - Triggering
Remote programming – triggering Trigger model (remote operation) The following paragraphs describe how the Model 2701 operates for remote operation. The flow chart in Figure 8-10 summarizes operation over the bus. The flow chart is called the trigger model because operation is controlled by SCPI commands from the Trigger subsystem.
Page 267 Model 2701 User’s Manual Triggering 8-17 Figure 8-10 Trigger model (remote operation) :ABOrt *RCL <NRf> START :SYST:PRES *RST :INIT (:IMM) Idle :INIT:CONT ON Initiate :INIT (:IMM) :INIT:CONT ON :Trigger:Signal Another Trigger Event Control Detection Source :Trigger:Count<n> | INFinity :Trigger:Source Immediate...
Page 268: Trigger Model Operation
MANual — Event detection is satisfied by pressing the TRIG key. The Model 2701 must be in LOCAL mode for it to respond to the TRIG key. Press the LOCAL key or send SYSTem:LOCal via the Ethernet or RS-232 to remove the instrument from the remote mode.
Page 269: Triggering Commands
Triggering 8-19 Output Trigger — The Model 2701 will send one or more output triggers. The output trigger is applied to the Trigger Link connector on the rear panel. It can be used to trigger an external instrument to perform an operation.
Page 270: Programming Example
Triggering Model 2701 User’s Manual Reference ABORt — With continuous initiation disabled, the 2701 goes into the idle state. With continuous initiation enabled, operation continues at the top of the trigger model. INITiate — Whenever the instrument is operating within the trigger model, sending this command causes an error and will be ignored.
Page 271: Limits And Digital I/O
Limits and Digital I/O • Limits — Explains how to perform limit tests on measured readings. • Digital I/O — Covers the digital I/O port. Explains how the five digital outputs respond to the results of limit tests. • Remote programming — limits and digital output — Summarizes the commands to perform limit tests and control the digital I/O port.
Page 272: Limits
Limits and Digital I/O Model 2701 User’s Manual Limits NOTE Limits cannot be used with the CONT function. When using limits, you can set and control the values that determine the HIGH/IN/LOW status of subsequent measurements. The limit test is performed on the result of an enabled Rel, Math, Ratio, or Channel Average operation.
Page 273 The LOW annunciator is not used for an overflow reading. An overflow reading is interpreted by the Model 2701 as a positive reading, even if the input signal is negative. That is the reason why the LOW annunciator does not turn on.
Page 274: Scanning
Limits and Digital I/O Model 2701 User’s Manual Scanning When a simple scan is configured, the present limit values and state will apply to all channels in the scan. When an advanced scan is configured, each channel can have its own unique limits configuration.
Page 275: Digital I/O
Model 2701 User’s Manual Limits and Digital I/O Digital I/O Model 2701’s Digital I/O port is accessed at a male DB-9 connector located on the rear panel. The connector location and pin designations are shown in Figure 9-2. Figure 9-2...
Page 276: Digital Outputs
Limits and Digital I/O Model 2701 User’s Manual Digital outputs The digital I/O port has five digital outputs. Each digital output can be used as a sink to control devices (e.g., relays) or as a source to provide input to external logic (TTL or CMOS) circuitry.
Page 277 Model 2701 User’s Manual Limits and Digital I/O Logic sense The selected logic sense (active high or active low) determines if an output is pulled high or low when the limit is reached. If logic sense is set high, the output line will be pulled high when the reading reaches or exceeds the limit.
Page 278 Limits and Digital I/O Model 2701 User’s Manual Sink mode — controlling external devices Each output can be operated from an external supply (voltage range from +5V to +33V applied through the external device being driven). The high current sink capacity of the output driver allows direct control of relays, solenoids, and lamps (no additional circuitry needed).
Page 279 Model 2701 User’s Manual Limits and Digital I/O Figure 9-4 Controlling externally powered relays Model 2701 Pin 7 - Diode Clamp Relay Coil Digital Output #1 4.75kW Flyback Diode Pull Up Resistor External Power (+5V to +33V) Digital Output Control...
Page 280: Setting Digital Output
Each output line can source up to 200µA. Exceeding 200µA may cause damage to Model 2701 that is not covered by the warranty. Figure 9-5 shows how to connect a logic device to one of the output lines. When the output line is pulled high, the transistor will turn off (transistor switch open) to provide a reliable logic high output (>3.75V).
Page 281: Scanning
While limits can be configured on a per scan channel basis, the digital output configura- tion cannot. Therefore, for all scan channels that are set to use limits, the digital output will function according to how the Model 2701 is set up when the scan is run.
Page 282: Remote Programing - Limits And Digital Output
9-12 Limits and Digital I/O Model 2701 User’s Manual Remote programing — limits and digital output Limits and digital output commands The limits and digital output commands are provided in Table 9-2. Table 9-2 Limits and digital I/O commands Commands...
Page 283 Model 2701 User’s Manual Limits and Digital I/O 9-13 NOTE When measurements are performed, the readings are fed to other enabled operations, including Limits. Appendix D explains “Data flow (remote operation)” and the commands used to read the result of limit tests.
Page 284: Limits And Digital Outputs Programming Example
5%. Bin 3 is for resistors that exceed 5% tolerance. The digital outputs of the Model 2701 can be used to further automate the test system by controlling a compatible component handler to perform the binning operations.
Page 285 Model 2701 User’s Manual Limits and Digital I/O 9-15 Figure 9-6 Ω Setup to test 100 resistors A) Front panel inputs Sense HI Model 2701 Input HI 100Ω Input LO Sense LO B) Model 7700 Model 7700 Switching CH 11-20...
Page 286 9-16 Limits and Digital I/O Model 2701 User’s Manual The limits are illustrated in Figure 9-7. Figure 9-7 Ω Limits to sort 100 resistors (1%, 5%, and >5%) Beep Beep Beep No Beep (low pitch) (normal pitch) (low pitch) No Beep...
Page 287: Digital Outputs
Model 2701 User’s Manual Limits and Digital I/O 9-17 Digital outputs With the digital outputs of the Model 2701 enabled, the digital outputs will respond as follows for each resistor reading: Resistor Affected LO limit 2 LO limit 1 HI limit 1...
Page 288: Remote Operations
Front panel aspects of Ethernet operation — Summarizes error messages, status indicators, and using the LOCAL key. • Programming syntax — Describes the basic programming syntax for both common and SCPI commands. • RS-232 interface operation — Outlines use of the RS-232 interface to control the Model 2701.
Page 289: Operation Enhancements
A pseudocard cannot be installed from the front panel. However, once it is installed, you can take the Model 2701 out of remote and use the front panel. When the instrument is turned off, the pseudocard will be lost (uninstalled).
Page 290: Separate Function Setups
RS-232 interface are provided in Table 10-3. NOTE The Model 2701 has an internal web page. From this web page, you can send commands to the 2701 and take readings. See “Internal web page” for details.
Page 291: Password
Remote Operations Model 2701 User’s Manual Password A user-defined password can be used to disable protected commands. Most Model 2701 commands are protected. When the use of password is enabled, there are commands to either disable or enable the protected commands.
Page 292: Battery
Model 2701 User’s Manual Remote Operations 10-5 • Enable protected commands. This takes the Model 2701 out of the password- protected mode. Example using “DEFAULT” as the password: SYSTem:PASSword:CENable “DEFAULT” • Query the password protection state (enabled or disabled). Example: SYSTem:PASSword:CENable:STATe? •...
Page 293: Miscellaneous System Commands
Also included in Table 10-1 are system commands to control remote/local operation, re- boot the 2701, and acquire the serial number and revision of the main PC board. System commands not covered in this section are provided in Section 14. All SYSTem commands are listed in Table 15-7.
Page 294: Ethernet Setup
The four typical Ethernet systems using a Model 2701 are shown in Figures 10-1 through 10-4. The simplest system connects a Model 2701 directly to a PC equipped with a NIC (Network Interface Card) as shown in Figure 10-1. The Ethernet cable can be up to 100 meters in length.
Page 295 10-8 Remote Operations Model 2701 User’s Manual Adding a hub as shown in Figure 10-2, expands the system into a small LAN (Local Area Network). The hub allows additional Ethernet instruments to be connected to the PC. Figure 10-2 Small LAN system using a hub...
Page 296 Model 2701 User’s Manual Remote Operations 10-9 Figure 10-3 Isolated LAN system using two NICs (Network Interface Cards) LInk/Act 100bT DIGITAL I/O TRIG. LINK ETHERNET RS232 (EXT. TRIG.) 10/100 BaseT Link/Act 100bT DIGITAL I/O TRIGGER ETHERNET RS-232 (EXT. TRIG.) LINK...
Page 297: Ethernet Connections
(see Figure 10-5). The Ethernet connector for the Model 2701 is shown in Figure 10-6. With power off, connect one end of the cable to the Model 2701 and connect the other end to the Ethernet connector of the PC, hub, or receptacle.
Page 298 Model 2701 User’s Manual Remote Operations 10-11 Figure 10-6 Model 2701 Ethernet connector Link/Act 100bT ETHERNET 10/100 BaseT Link/Act 100bT DIGITAL I/O TRIGGER ETHERNET RS-232 (EXT. TRIG.) LINK 10/100 BaseT ~LINE RATING 50, 60, 400Hz 28VA MAX...
Page 299: Ethernet Settings
• Ethernet gateway • MAC address of the 2701 – This fixed address for the 2701 cannot be changed. Ethernet settings can be made from either the front panel or remote programming. NOTE Error code +550 Unitialized Ethernet module will occur on power-up if the Ethernet settings are corrupt or the MAC address is FF:FF:FF:FF:FF:FF.
Page 300 Model 2701 User’s Manual Remote Operations 10-13 Front panel Ethernet setup The front panel Ethernet menu provides two options: VIEW and SET. The VIEW is used to check the present Ethernet settings. Settings cannot be changed from this menu stucture. The SET option is used to change the Ethernet settings.
Page 301 Press ENTER See Op Note 2 Op Notes: 1. If Ethernet was off, turning it on will cause the 2701 to re-boot. To change Ethernet settings, return to the beginning of this flowchart and start over. 2. After pressing ENTER for the Gateway4 settting, the 2701 will re-boot.
Page 302 :GATeway <value> Set the Ethernet gateway; “n.n.n.n”. :GATeway? Query the Ethernet gateway. :DHCP Enable or disable Dynamic Host Control Protocol (DHCP). :DHCP? Query state of DHCP. :MAC? Returns MAC address of 2701; 6 hexadecimal values separated by colons (00:60:1A:00:04:0B).
Page 303: Internal Web Page
Opening the web page System requirements Internet Explorer (IE 5.0 or greater) is needed to open the 2701 web page. Make sure the PC and Model 2701 is properly set for Ethernet operation. Details on using the Ethernet is provided in the Model 2701 Instrument Networking Instruction Manual. The following example demonstrates correct settings for the Model 2701 and the PC: Example –...
Page 304 Remote Operations 10-17 As shown above for the IP Address, the Network ID of the 2701 and PC must be the same. The Node Designators must be different. However the Subnet mask must be the same for the 2701 and the PC.
Page 305 10-18 Remote Operations Model 2701 User’s Manual Figure 10-9 Model 2701 Configuration internal web page...
Page 306 Model 2701 User’s Manual Remote Operations 10-19 Figure 10-10 Web page control panel NOTE After you send a command it is recommended that you add the system error query (for instance, TRIG:COUN 20;:SYST:ERR?) to make sure errors did not occur from the sent command. For example, append :SYST:ERR? to the end of any command to check the status.
Page 307: Front Panel Aspects Of Ethernet Operation
10-20 Remote Operations Model 2701 User’s Manual Front panel aspects of Ethernet operation This section describes aspects of the front panel that are part of Ethernet operation, includ- ing messages, status indicators, and the LOCAL key. Error and status messages See Appendix C for a list of error and status messages associated with programming.
Page 308: Programming Syntax
Model 2701 User’s Manual Remote Operations 10-21 Programming syntax The information in this section covers syntax for both common commands and SCPI com- mands. For information not covered here, see the IEEE-488.2 and SCPI standards. See Sections 12 through 15 for more details on common and SCPI commands.
Page 309 10-22 Remote Operations Model 2701 User’s Manual <name> Name parameter — Select a parameter name from a listed group. Example: <name> = NEVer = NEXt = ALWays TRACe:FEED:CONTrol NEXt <NRf> Numeric representation format — This parameter is a number that can be expressed as an integer (e.g., 8), a real number (e.g., 23.6), or an exponent...
Page 310: Query Commands
Model 2701 User’s Manual Remote Operations 10-23 Query commands This type of command requests (queries) the presently programmed status. It is identified by the question mark (?) at the end of the fundamental form of the command. Most commands have a query form: TRIGger:TIMer? Queries the timer interval.
Page 311: Short-Form Rules
10-24 Remote Operations Model 2701 User’s Manual Short-form rules Use the following rules to determine the short-form version of any SCPI command: • If the length of the command word is four letters or less, no short form version exists. Example:...
Page 312 Model 2701 User’s Manual Remote Operations 10-25 Single command messages The above command structure has three levels. The first level is made up of the root command (STATus) and serves as a path. The second level is made up of another path (:OPERation) and a command (:PRESet).
Page 313 10-26 Remote Operations Model 2701 User’s Manual Command path rules • Each new program message must begin with the root command, unless it is optional (e.g., [SENSe]). If the root is optional, simply treat a command word on the next level as the root. For fastest operation, do not send optional data.
Page 314: Response Messages
Message exchange protocol Two rules summarize the message exchange protocol: Rule 1. You must always tell the Model 2701 what to send to the computer. The following two steps must always be performed to send information from the instrument to the computer: Send the appropriate query command(s) in a program message.
Page 315: Rs-232 Interface Operation
EXIT. The next command to send buffer data (i.e., TRACe:DATA?) will start at the beginning, rather than where the transmission was halted. Baud rate The baud rate is the rate at which the Model 2701 multimeter and the programming terminal communicate. Choose one these available rates: •...
Page 316: Signal Handshaking (Flow Control)
(RTS and CTS) for this purpose (see Figure 10-11 and Table 10-4.) When the 2701 is ready to send (RTS) data, it will transmit when it receives the clear to send (CTS) signal from the computer.
Page 317: Terminator
10-30 Remote Operations Model 2701 User’s Manual Terminator The Model 2701 can be configured to terminate each program message that it transmits to the controller with any of the following combinations of <CR> and <LF>. <CR> Carriage return <CR+LF> Carriage return and line feed <LF>...
Page 318 Model 2701 User’s Manual Remote Operations 10-31 The commands to select and configure the RS-232 interface are listed in Table 10-3. Table 10-3 SYSTem commands to configure RS-232 Command Description :COMMunicate Ethernet and RS-232 (serial) commands: :SELect <name> Select communications mode; SERial or ETHernet...
Page 319: Rs-232 Connections
10-32 Remote Operations Model 2701 User’s Manual RS-232 connections The RS-232 serial port is connected to the serial port of a computer using a straight- through RS-232 cable terminated with DB-9 connectors. Do not use a null modem cable. The serial port uses the transmit (TXD), receive (RXD), ready to send (RTS), clear to send (CTS), and signal ground (GND) lines of the RS-232 standard.
Page 320: Error Messages
Model 2701 User’s Manual Remote Operations 10-33 Table 10-5 provides pinout identification for the 9-pin (DB-9) or 25-pin (DB-25) serial port connector on the computer (PC). Table 10-5 PC serial port pinout Signal DB-9 pin # DB-25 pin # DCD, data carrier detect...
Page 321: Status Structure
Status Structure • Overview — Provides an operational overview of the status structure for the Model 2701. • Clearing registers and queues — Covers the actions that clear (reset) registers and queues. • Programming and reading registers — Explains how to program enable registers and read any register in the status structure.
Page 322: Overview
Model 2701 User’s Manual Overview The Model 2701 provides a series of status registers and queues allowing the operator to monitor and manipulate the various instrument events. The status structure is shown in Figure 11-1. The heart of the status structure is the Status Byte Register. This register can be read by the user’s test program to determine if a service request (SRQ) has occurred...
Page 323 Model 2701 User’s Manual Status Structure 11-3 Figure 11-1 Model 2701 status register structure Questionable Questionable Questionable Condition Event Event Enable Register Register Register & & & & Temperature Summary Temp Temp Temp & & & Logical & Calibration Summary &...
Page 324: Clearing Registers And Queues
Model 2701 User’s Manual Clearing registers and queues When the Model 2701 is turned on, the bits of all registers in the status structure are cleared (reset to 0) and the two queues are empty. Commands to reset the event, event enable registers, and the Error Queue are listed in Table 11-1.
Page 325: Programming And Reading Registers
Model 2701 User’s Manual Status Structure 11-5 Programming and reading registers Programming enable registers The only registers that can be programmed by the user are the enable registers. All other registers in the status structure are read-only registers. The following explains how to ascertain the parameter values for the various commands used to program enable registers.
Page 326 11-6 Status Structure Model 2701 User’s Manual The <NDN> (non-decimal numeric) parameter type is used to send non-decimal values. These values require a header (#B, #H, or #Q) to identify the data format being sent. The letter in the header can be upper or lower case. The <NRf> (numeric representation format) parameter type is used to send decimal values and does not use a header.
Page 327: Reading Registers
Model 2701 User’s Manual Status Structure 11-7 Reading registers Any register in the status structure can be read by using the appropriate query (?) com- mand. The following explains how to interpret the returned value (response message). The actual query commands are covered later in this section.
Page 328: Status Byte And Service Request (Srq)
11-8 Status Structure Model 2701 User’s Manual Status byte and service request (SRQ) Service request is controlled by two 8-bit registers: the Status Byte Register and the Service Request Enable Register. Figure 11-3 shows the structure of these registers. Figure 11-3...
Page 329: Service Request Enable Register
Model 2701 User’s Manual Status Structure 11-9 The bits of the Status Byte Register are described as follows: • Bit B0, Measurement Summary Bit (MSB) — Set summary bit indicates that an enabled measurement event has occurred. • Bit B1 — Not used.
Page 330: Status Byte And Service Request Commands
' Read Status Byte Register. Status register sets As shown in Figure 11-1, there are four status register sets in the status structure of the Model 2701: Standard Event Status, Operation Event Status, Measurement Event Status, and Questionable Event Status.
Page 331: Register Bit Descriptions
Bit B0, Operation Complete (OPC) — Set bit indicates that all pending selected device operations are completed and the Model 2701 is ready to accept new com- mands. This bit only sets in response to the *OPC? query command. See Section 12 for details on *OPC and *OPC?.
Page 332 Bit B6, User Request (URQ) — Set bit indicates that the LOCAL key on the Model 2701 front panel was pressed. • Bit B7, Power On (PON) — Set bit indicates that the Model 2701 has been turned off and turned back on since the last time this register has been read.
Page 333 Bit B4, Measuring (Meas) — Set bit indicates that the instrument is performing a measurement. • Bit B5, Waiting for Trigger (Trig) — Set bit indicates that the Model 2701 is in the trigger layer waiting for a trigger event to occur. •...
Page 334 11-14 Status Structure Model 2701 User’s Manual Measurement event register The used bits of the Measurement Event Register (Figure 11-6) are described as follows: • Bit B0, Reading Overflow (ROF) — Set bit indicates that the reading exceeds the measurement range of the instrument.
Page 335 Model 2701 User’s Manual Status Structure 11-15 • Bit B14, Master Limit (ML) — Set bit indicates that one or more of the other limits have been reached or exceeded. • Bit B15 — Not used. Figure 11-6 Measurement event status...
Page 336 11-16 Status Structure Model 2701 User’s Manual Questionable event register The used bits of the Questionable Event Register (Figure 11-7) are described as follows: • Bits B0 through B3 — Not used. • Bit B4, Temperature Summary (Temp) — Set bit indicates that an invalid reference junction measurement has occurred for thermocouple temperature measurements.
Page 337: Condition Registers
For example, while the Model 2701 is in the idle state, bit B10 (Idle) of the Operation Condition Register will be set. When the instrument is taken out of idle, bit B10 clears.
Page 338: Event Registers
11-18 Status Structure Model 2701 User’s Manual Event registers As Figure 11-1 shows, each status register set has an event register. When an event occurs, the appropriate event register bit sets to 1. The bit remains latched to 1 until the register is reset.
Page 339 Model 2701 User’s Manual Status Structure 11-19 Table 11-6 Event enable registers commands Command Description *ESE <NDN> or <NRf> Program Standard Event Enable Register. *ESE? Read Standard Event Enable Register. STATus:OPERation:ENABle <NDN> or <NRf> Program Operation Event Enable Register. STATus:OPERation:ENABle? Read enable register.
Page 340 Example 2 – Read RAV bit of measurement event register The following command sequence demonstrates the proper method to read the RAV bit of the measurement event register: *RST ' Put 2701 in “one-shot” mode. *CLS ' Clear measurement event register. STAT:PRES ' Clear measurement event enable register.
Page 341 TRAC:POIN 500 ' Sets buffer size to 500 readings. TRAC:FEED SENS ' Sets to store raw readings. TRIG:COUN 500 ' Sets 2701 to perform 500 measurements. TRAC:FEED:CONT NEXT ' Enables buffer. INIT ' Starts measurement and storage process. *OPC ' Sets OPC bit B0 of standard event register after the ' measure-store process is finished.
Page 342: Queues
Output Queue — Used to hold reading and response messages. • Error Queue — Used to hold error and status messages. The Model 2701 status model (Figure 11-1) shows how the two queues are structured with the other registers. Output queue The Output Queue holds data that pertains to the normal operation of the instrument.
Page 343 Model 2701 User’s Manual Status Structure 11-23 On power-up, all error messages are enabled and will go into the Error Queue as they occur. Status messages are not enabled and will not go into the queue. As listed in Table 11-7, there are commands to enable and/or disable messages. For these commands, the <list>...
Page 344: Common Commands
Common Commands...
Page 345 Returns the model numbers of the switching modules installed in the Model 2701. Returns “NONE” if a slot is empty. *RCL <NRf> Recall command Returns Model 2701 to the user-saved setup (0, 1, 2, 3, or 4). *RST Reset command Returns Model 2701 to the *RST default conditions.
Page 346 When used with the immediate initiation command (:INITiate), the OPC bit in the Standard Event Status Register will not set until the Model 2701 goes back into the idle state. The :INIT command operation is not considered finished until the Model 2701 goes back into the idle state.
Page 347 When used with the Initiate Immediately command (:INITiate), a “1” will not be placed into the Output Queue until the Model 2701 goes back into the idle state. The :INIT command operation is not considered finished until the Model 2701 goes back into the idle state.
Page 348 Query installed switching modules Use this query command to determine which switching modules are installed in the Model 2701. For example, if a Model 7703 is installed in slot 1 and the other slot is empty, the response message will look like this: 7703, NONE Note that the model number of an installed pseudocard is returned in the same manner.
Page 349 F *RST — reset Return Model 2701 to RST defaults When the *RST command is sent, Model 2701 performs the following operations: Returns Model 2701 to the RST default conditions (see “Default” column of SCPI tables). Cancels all pending commands.
Page 350 G *TRG — trigger Send bus trigger to Model 2701 Use the *TRG command to issue a trigger to Model 2701. Use the *TRG command as an event to control operation. Model 2701 reacts to this trigger if BUS is the programmed arm control source.
Page 351 See *OPC, *OPC?, and *TRG for more information. The INITiate commands remove the Model 2701 from the idle state. The device operations of :INITiate are not considered complete until the Model 2701 returns to idle. By sending the *WAI command after the INITiate command, all subsequent commands will not execute until the Model 2701 goes back into idle.
Page 352: Scpi Signal Oriented Measurement Commands
SCPI Signal Oriented Measurement Commands...
Page 353 Table 13-1 Signal oriented measurement command summary Command Description CONFigure:<function> [<rang>], [<res>], [<clist>] Places the Model 2701 in a “one-shot” measurement mode for the specified function. FETCh? Requests the latest reading. READ? Performs an ABORt, INITiate, and FETCh?. MEASure[:<function>]? [<rang>], [<res>], [<clist>] Performs an ABORt, CONFigure:<function>, and...
Page 354 Model 2701 User’s Manual SCPI Signal Oriented Commands 13-3 NOTE The CONFigure:<function> and MEASure:<function>? commands can be sent without any of the optional parameters (<rang>, <res>, <clist>). For details, see the “Description” for the CONFigure and MEASure commands. When using the <clist> parameter, it is interpreted as the last parameter. Any parameter after <clist>...
Page 355: Configure: [], [], []
13-4 SCPI Signal Oriented Commands Model 2701 User’s Manual CONFigure:<function> [<rang>], [<res>], [<clist>] CONFigure:VOLTage[:DC] [<rang>], [<res>], [<clist>] Configure DCV CONFigure:VOLTage:AC [<rang>], [<res>], [<clist>] Configure ACV CONFigure:CURRent[:DC] [<rang>], [<res>], [<clist>] Configure DCI CONFigure:CURRent:AC [<rang>], [<res>], [<clist>] Configure ACI Configure Ω2 CONFigure:RESistance [<rang>], [<res>], [<clist>] Configure Ω4...
Page 356 The count values of the Trigger Model are set to one. • The delay of the Trigger Model is set to zero. • The Model 2701 is placed in the idle state. • All math calculations are disabled. • Buffer operation is disabled. A storage operation presently in process will be aborted.
Page 357: Fetch
Description This command requests the latest post-processed reading. After sending this command and addressing the Model 2701 to talk, the reading is sent to the computer. This command does not affect the instrument setup. This command does not trigger a measurement. The command simply requests the last available reading.
Page 358: Read
INIT or READ? command if sample count is >1 (error -225, out of memory). Buffer operation is covered in Section 6. The buffer of the Model 2701 is nonvolatile. Therefore, readings stored in the buffer are not lost when the instrument is turned off or when *RST or SYSTem:PRESet is sent.
Page 359: Measure:? [], [], []
13-8 SCPI Signal Oriented Commands Model 2701 User’s Manual MEASure:<function>? [<rang>], [<res>], [<clist>] MEASure:VOLTage[:DC]? [<rang>], [<res>], [<clist>] Measure DCV MEASure:VOLTage:AC? [<rang>], [<res>], [<clist>] Measure ACV MEASure:CURRent[:DC]? [<rang>], [<res>], [<clist>] Measure DCI MEASure:CURRent:AC? [<rang>], [<res>], [<clist>] Measure ACI Measure Ω2 MEASure:RESistance? [<rang>], [<res>], [<clist>] Measure Ω4...
Page 360 Model 2701 User’s Manual SCPI Signal Oriented Commands 13-9 Depending on the specified resolution, the measurement rate is set as follows: 6½-digits NPLC = 1.0 Medium 5½-digits NPLC = 0.1Fast 3½ or 4½-digits NPLC = 0.01>Fast If resolution is not specified, 6½-digit resolution and medium speed will be selected when MEAS? is sent.
Page 361: Format And Miscellaneous System Commands
FORMat and Miscellaneous SYSTem Commands • FORMat commands — Covers the SCPI commands to configure the format that readings are transmitted. • Miscellaneous SYSTem commands — Covers miscellaneous SYSTem commands.
Page 362: Format Commands
14-2 FORMat and Misc SYSTem Commands Model 2701 User’s Manual FORMat commands The commands in this subsystem (Table 14-1) are used to select the elements for acquired readings and to select the data format for reading status event registers. NOTE Details on the FORMat:SREGister command are provided in Section 11 (see “Programming and reading registers”).
Page 363 TRACe:TSTamp:FORMat ' Select timestamp format; ABSolute or DELTa. Reading number — The reading counter starts at zero when the Model 2701 is turned on. When returning buffer readings using TRACe:DATA?, each reading will be referenced to the first reading, which is #0. The following command will reset the counter: SYSTem:RNUMber:RESet.
Page 364: Miscellaneous System Commands
*OPC or *OPC? should be used with SYST:PRES, which is slow responding command. Details on *OPC and *OPC? are provided in Section 12. SYSTem:VERSion Read the version of the SCPI standard being used by Model 2701. Example response message: 1996.0. SYSTem:KEY <NRf>...
Page 365: System:beeper[:State]
Enable beeper Figure 14-2 Key-press codes INTEGRA SERIES SENSE INPUT Ω4 WIRE 350V 1000V PEAK PEAK 2701 ETHERNET MULTIMETER / DATA ACQUISITION SYSTEM 500V RATIO CH AVG CONT OCOMP MATH O U T P U T PERIOD SENSOR PEAK INPUTS Ω2 Ω4...

Page 366: Scpi Reference Tables
SCPI Reference Tables...
Page 367: Reference Tables
SCPI Reference Tables Model 2701 User’s Manual Reference tables Table 15-1 through Table 15-10 summarize the commands to operate the Model 2701 and Model 7700 switching module. NOTE The commands listed in the following tables pertain to operation of the Model 2701 and the Model 7700 switching module.
Page 368 Model 2701 User’s Manual SCPI Reference Tables 15-3 Table 15-1 CALCulate command summary Default Command Description parameter SCPI CALCulate[1] Subsystem to control CALC 1: Sec 5 :FORMat <name> Select math format (NONE, MXB, PERCent, or PERCent [<, clist>] RECiprocal). :FORMat? [<clist>] Query math format.
Page 369 15-4 SCPI Reference Tables Model 2701 User’s Manual Table 15-1 (continued) CALCulate command summary Default Command Description parameter SCPI CALCulate3 Subsystem to control CALC 3 (limit test): Sec 9 :MLIMit Path for master limit command: :LATChed Enable or disable master limit latch.
Page 370 Model 2701 User’s Manual SCPI Reference Tables 15-5 Table 15-1 (continued) CALCulate command summary Default Command Description parameter SCPI CALCulate3 :LIMit2 Path to control LIMIT 2 test: :UPPer Path to configure upper limit: [:DATA] <n> Set upper limit (-4294967295 to [, <clist>]...
Page 371 15-6 SCPI Reference Tables Model 2701 User’s Manual Table 15-3 FORMat command summary Default Command Description parameter SCPI FORMat :ELEMents <item list> Specify data elements (READing, CHANnel, (see Note) Sec 14 UNITs, RNUMber, TSTamp, and LIMits). :ELEMents? Query data elements.
Page 372 Model 2701 User’s Manual SCPI Reference Tables 15-7 Table 15-4 (continued) ROUTe command summary Default Command Description parameter SCPI ROUTe :MULTiple Path to control multiple channels: Sec 2 :OPEN <clist> Open channel(s) specified in list. Unlisted channels not affected. :CLOSe <clist>...
Page 373 15-8 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :FUNCtion <name> Select function: ‘VOLTage[:DC]’, VOLT:DC Sec 3 [, <clist>] ‘VOLTage :AC’, ‘CURRent[:DC]’, ‘CURRent:AC’, ‘RESistance’, ‘FRESistance’, ‘TEMPerature’, ‘FREQuency’, ‘PERiod’, ‘CONTinuity’. :FUNCtion? [<clist>] Query function.
Page 374 Model 2701 User’s Manual SCPI Reference Tables 15-9 Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :VOLTage[:DC] Path to configure DC voltage. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 375 15-10 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :VOLTage:AC Path to configure AC voltage. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 376 Model 2701 User’s Manual SCPI Reference Tables 15-11 Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :CURRent[:DC] Path to configure DC current. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 377 15-12 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :CURRent:AC Path to configure AC current. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 378 Model 2701 User’s Manual SCPI Reference Tables 15-13 Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :RESistance Path to configure resistance. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 379 15-14 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :FRESistance Path to configure four-wire resistance. Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 380 Model 2701 User’s Manual SCPI Reference Tables 15-15 Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :TEMPerature Path to configure temperature: Sec 3 :APERture <n> [, <clist>] Set integration rate in seconds (Note 2) Sec 4 (3.333333e-5 to 1).
Page 381 15-16 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :TEMPerature :TCouple Path to configure thermocouple: Sec 3 [:TYPE] <type> Select T/C type (J, K, T, E, R, S, B, N).
Page 382 Model 2701 User’s Manual SCPI Reference Tables 15-17 Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :FREQuency Path to configure frequency. Sec 3 :APERture <n> [, <clist>] Sets gate time for frequency Sec 4 measurements in seconds (0.01 to 1.0).
Page 383 15-18 SCPI Reference Tables Model 2701 User’s Manual Table 15-5 (continued) SENSe command summary Default Command Description parameter SCPI [SENSe[1]] :CONTinuity Path to configure continuity test: Sec 3 :THReshold <NRf> Set threshold resistance in ohms (1 to 1000). :THReshold? Query threshold resistance.
Page 384 Model 2701 User’s Manual SCPI Reference Tables 15-19 Table 15-6 STATus command summary Default Command Description parameter SCPI STATus (Note 1) Sec 11 :MEASurement Measurement event registers: [:EVENt]? Read the event register. (Note 2) :ENABle <NDN> or <NRf> Program the enable register.
Page 385 15-20 SCPI Reference Tables Model 2701 User’s Manual Table 15-7 SYSTem command summary Default Command Description parameter SCPI SYSTem :PRESet Return to :SYST:PRES defaults. Sec 14 :POSetup <name> Select power-on setup: (RST, PRESet, SAV0, Sec 1 SAV1, SAV2, SAV3, or SAV4).
Page 386 Model 2701 User’s Manual SCPI Reference Tables 15-21 Table 15-7 (continued) SYSTem command summary Default Command Description parameter SCPI SYSTem :CARDX :TCOMpensated? Built-in temperature sensors for T/C cold junction?; 1 = yes, 0 = no. :VCHannel Path to query volts/2-wire channels:...
Page 387 Clears messages from the Error Queue. Sec 11 :VERSion? Query rev level of SCPI standard. Sec 14 :LOCal Take 2701 out of remote and restore operation of front panel controls. :REMote Place 2701 in remote. :RWLock Lockout front panel controls.
Page 388 Ethernet and RS-232 commands: :SELect <name> Select communications mode; ETHernet or SERial. :ETHernet Ethernet: :ADDRess <value> Set IP address of 2701; “n.n.n.n”. :ADDRess? Query IP address of 2701. :MASK <value> Sets the subnet mask; “n.n.n.n”. :MASK? Query subnet mask. :GATeway <value>...
Page 389 SCPI SYSTem :COMMunicate :ETHernet :DHCP? Query state of DHCP. :MAC? Returns MAC address of 2701; 6 hexadecimal values separated by colons (00:60:1A:00:04:0B). :SERial RS-232: :BAUD <n> Set baud rate; 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, or 115200.
Page 390 Model 2701 User’s Manual SCPI Reference Tables 15-25 Table 15-8 TRACe command summary Default Command Description parameter* SCPI TRACe|:DATA Use TRACe or DATA as root command. Sec 6 :CLEar Path to clear the buffer. [:IMMediate] Clear the buffer. :AUTO ...
Page 391 15-26 SCPI Reference Tables Model 2701 User’s Manual Table 15-9 Trigger command summary Default Command Description parameter SCPI INITiate Subsystem command path: Sec 8 [:IMMediate] Initiate one trigger cycle. :CONTinuous Enable or disable continuous initiation. (Note 1) :CONTinuous? Query continuous initiation.
Page 392 Model 2701 User’s Manual SCPI Reference Tables 15-27 Table 15-10 UNIT command summary Default Command Description parameter SCPI UNIT :TEMPerature <name> Select temperature units (C, CEL, F, Sec 3 FAR, or K). :TEMPerature? Query temperature units. :VOLTage Path to configure voltage units.
Page 393 Specifications...
Page 394: Model 2701 Ethernet / Data Acquisition System
Specifications Model 2701 User’s Manual Model 2701 Ethernet / Data Acquisition System Put 2701 specs here...
Page 395: Accuracy Calculations
Model 2701 User’s Manual Specifications Accuracy calculations The information below discusses how to calculate accuracy for both DC and AC characteristics. Calculating DC characteristics accuracy DC characteristics accuracy is calculated as follows: Accuracy = ±(ppm of reading + ppm of range) (ppm = parts per million and 10ppm = 0.001%)
Page 396: Calculating Dbm Characteristics Accuracy
Specifications Model 2701 User’s Manual Calculating dBm characteristics accuracy As an example of how to calculate the actual reading limits for a 13dBm measurement with a reference impedance of 50Ω , assume an applied signal of 0.998815V. The relationship between voltage and dBm is as follows: ⁄...
Page 397: Calculating Db Characteristics Accuracy
Model 2701 User’s Manual Specifications Calculating dB characteristics accuracy The relationship between voltage and dB is as follows: ----------- - As an example of how to calculate the actual readings limits for dB, with a user-defined VREF of 10V, you must calculate the voltage accuracy and apply it to the above equation.
Page 398: Optimizing Measurement Accuracy
A-10 Specifications Model 2701 User’s Manual Optimizing measurement accuracy The configurations listed below assume that the multimeter has had factory setups restored. NOTE For maximum system performance, it is recommended that all measurement cables be limited to less than 3 meters.
Page 399: Model 7700 Connection Guide
Model 7700 Connection Guide...
Page 400: Card Configuration - Schematic
AMP and LO common connections to the DMM are also provided. Channel 23 (2W/4W Configuration), Channel 24 (Sense Isolation), and Channel 25 (Input Isolation) are normally automatically configured by the 2701 for system channel operation. However, by using multiple channel operation (refer to Section 2), channels can be individually controlled.
Page 401 Model 2701 User’s Manual Model 7700 Connection Guide Figure B-1 Simplified schematic for Model 7700 Input Sense HI Cold Junction Ref x3 Channel 1 Channel 25 (See Note) (Channels 2–9) Backplane Isolation Channel 10 Input Channel 23 2-Pole (Open) Channel 24...
Page 402: Connections And Wiring
“High energy circuit safety precautions” in Section 3. As described in the International Electrotechnical Commission (IEC) Stan- dard IEC 664, the Model 2701 is Installation Category I and must not be connected to mains. Screw terminals Figure B-2 shows how to access the screw terminals on the Model 7700.
Page 403 Model 2701 User’s Manual Model 7700 Connection Guide Figure B-2 Screw terminal access LOCK CH10 INPUT (V, 2-WIRE) SENSE (OHMS, 4-WIRE) CH17 CH18 CH19 CH20 CH21 CH22 CH11 CH12 CH13 CH14 CH15 CH16 Figure B-3 Model 7700 screw terminal channel designations...
Page 404: Wiring Procedure
Model 7700 Connection Guide Model 2701 User’s Manual Wiring procedure Use the following procedure to wire the Model 7700 module. Make all connections using correct wire size (up to 20 AWG). Also, make sure to add supplementary insulation around the harness for voltages above 42V peak (Figure B-4).
Page 405 Model 2701 User’s Manual Model 7700 Connection Guide Figure B-4 Wire dressing Cable INPUT 2-WIRE) CH10 INPUT (V, 2-WIRE) Supplementary SENSE Insulation (OHMS, 4-WIRE) CH17 CH18 CH19 CH20 CH21 CH22 CH11 CH12 CH13 CH14 CH15 CH16...
Page 406: Typical Connections
Model 7700 Connection Guide Model 2701 User’s Manual Typical connections The following examples show typical wiring connections for the following types of measurements: • Thermocouple connections, Figure B-5 Ω2-Wire and thermistor connections, Figure B-6 • Ω4-Wire and RTD connections, Figure B-7 •...
Page 407 Model 2701 User’s Manual Model 7700 Connection Guide Figure B-7 Ω 4-Wire and RTD connections Resistor or Channel 1 4-Wire RTD (Channels 2-9) Resistor or Channel 10 4-Wire RTD Channel 11 (Channels 12-19) Channel 20 Figure B-8 Current connections (AC or DC)
Page 408: Connection Log
B-10 Model 7700 Connection Guide Model 2701 User’s Manual Figure B-9 Voltage connections (DC or AC) DC Voltage AC Voltage Channel 1 (Channels 2-19) Channel 20 Connection log Make a copy of Table B-1 and affix it to the cover of the Model 7700. Use this to record...
Page 409 Model 2701 User’s Manual Model 7700 Connection Guide B-11 Table B-1 Connection log Model 7700 Channel Color Description AMPS COM INPUT SENSE CH10 CH11 CH12 CH13 CH14 CH15 CH16 CH17 CH18 CH19 CH20 AMPS 21 AMPS 22...
Page 410: Status And Error Messages
Status and Error Messages...
Page 411 Status and Error Messages Model 2701 User’s Manual Table C-1 Status and error messages Number Description Event -440 Query unterminated after indefinite response -430 Query deadlocked -420 Query unterminated -410 Query interrupted -363 Input buffer overrun -350 Queue overflow -330...
Page 412 Model 2701 User’s Manual Status and Error Messages Table C-1 (continued) Status and error messages Number Description Event -158 String data not allowed -154 String too long -151 Invalid string data -150 String data error -148 Character data not allowed...
Page 413 Status and Error Messages Model 2701 User’s Manual Table C-1 (continued) Status and error messages Number Description Event +101 Operation complete +121 Device calibrating +122 Device settling +123 Device ranging +124 Device sweeping +125 Device measuring +126 Device calculating +161...
Page 414 Model 2701 User’s Manual Status and Error Messages Table C-1 (continued) Status and error messages Number Description Event Calibration messages: +400 10vdc zero error +401 100vdc zero error +402 10vdc full scale error +403 -10vdc full scale error +404 100vdc full scale error...
Page 415 Status and Error Messages Model 2701 User’s Manual Table C-1 (continued) Status and error messages Number Description Event +456 1 vac zero error +457 1 vac full scale error +458 1 vac noise error +459 10 vac zero error +460...
Page 416 Model 2701 User’s Manual Status and Error Messages Table C-1 (continued) Status and error messages Number Description Event +496 1 4-w dckt Ioff zero error +497 1 4-w dckt Ion zero error +498 1 4-w dckt Ion full scale error...
Page 417: Signal Processing Sequence And Data Flow
Signal Processing Sequence and Data Flow...
Page 418: Signal Processing Sequence
Figure D-1 is a flowchart that shows the basic processing sequence of an input signal. With all the various features (filter, rel, math, ratio, channel average, buffer, etc.) of the Model 2701 disabled, the input signal is conditioned and measured (A/D conversion process). The reading is then displayed on the Model 2701.
Page 419: Signal Processing Using Instrument Features
Model 2701 User’s Manual Signal Processing Sequence and Data Flow Signal processing using instrument features Figure D-2 shows the processing sequence for an input signal with various instrument features enabled. If a feature is not enabled, the reading simply falls through to the next enabled feature or to the display.
Page 420 For details on filter operation, see “Filter,” page 4-14. Output trigger pulse (VMC) An output trigger pulse from the Model 2701 can be used to trigger an external instrument to perform an operation. In general, a trigger pulse is the output at this point in the flowchart for each processed reading.
Page 421 The reading that is applied to the Limits block in the flow chart is not modified and is the reading that is displayed on the Model 2701. With Limits enabled, the reading is tested against two sets of high and low limits. Along with the displayed reading, annunciators and messages are used to indicate the result of the limits testing.
Page 422: Signal Processing Using Ratio Or Ch Avg
Signal Processing Sequence and Data Flow Model 2701 User’s Manual Signal processing using Ratio or Ch Avg With a switching module installed, the ratio or average of two channels can be calculated. Figure D-3 shows where Ratio or Ch Avg is calculated in the signal processing sequence.
Page 423: Data Flow (Remote Operation
Model 2701 User’s Manual Signal Processing Sequence and Data Flow Data flow (remote operation) Remote operation can be used with triggering configured to perform a specified number of measurements and then stop. The various read commands (SENS:DATA?, FETCh?, READ?, MEAS?, CALC2:DATA?, TRACe:DATA?, and CALC1:DATA?) return the data array(s) acquired during the measurement cycle.
Page 424: Sense And Sample Buffer
Signal Processing Sequence and Data Flow Model 2701 User’s Manual NOTE For the following discussion, a “data array” is defined as the group of data elements that are included with each measured reading. Each data array includes the reading, as well as the channel, reading number, units, timestamp, and limits result (see “FORMat:ELEMents <item list>,”...
Page 425: [Sens[1]]:Data[Latest]
That is, the data array reading must be “fresh.” Sending this command again to read the same (stale) data array will not work. It will generate an error (-230; data corrupt or stale) or cause the Model 2701 to time-out. In order for DATA:FRESh? to respond, you must first trigger a new (fresh) reading.
Page 426: Fetch
D-10 Signal Processing Sequence and Data Flow Model 2701 User’s Manual FETCh? READ? MEASure? CALC[1]:DATA[LATest]? CALC[1]:DATA:FRESh? As shown in Figure D-4, these commands are used to read data arrays output from the CALC1 Math block. However, if there is no math function enabled, these commands read the data arrays in the sample buffer.
Page 427: Calc3:Lim1:Fail
Model 2701 User’s Manual Signal Processing Sequence and Data Flow D-11 MEASure? The MEASure? command places the instrument in a “one-shot” measurement mode (which places one data array in the sample buffer) and then performs a READ?. With no math function enabled, the one data array in the sample buffer is read. With a math function enabled, the reading is the result of the math calculation.
Page 428: Calc2:Imm
D-12 Signal Processing Sequence and Data Flow Model 2701 User’s Manual CALC2:IMM? CALC2:IMM CALC2:DATA? Statistical information (minimum, maximum, mean, standard deviation, and peak-to-peak) is available for the readings stored in the buffer (data store). When the desired calculation is selected (using the CALC2:FORMat command) and CALC2 is enabled (CALC2:STATe ON), use the CALC2:IMM? or CALC2:IMM command to perform the calculation: •...
Page 429: Scanning
Model 2701 User’s Manual Signal Processing Sequence and Data Flow D-13 Scanning For remote operation, scanning is normally performed with continuous initiation disabled (INIT:CONT OFF). The sample count (SAMP:COUNt) specifies the number of channels to scan and store in the buffers (sample buffer and data store); the trigger count (TRIG:COUNt) specifies the number of scans to perform.
Page 430: Measurement Considerations
Measurement Considerations...
Page 431: Thermoelectric Potentials
Model 2701 User’s Manual Measurement considerations Low-level voltage measurements made using the Model 2701 can be adversely affected by various types of noise or other unwanted signals that can make it very difficult to obtain accurate voltage readings. Some of the phenomena that can cause unwanted noise include thermoelectric effects (thermocouple action), source resistance noise, magnetic fields, and radio frequency interference.
Page 432: Thermoelectric Generation
Model 2701 User’s Manual Measurement Considerations Thermoelectric generation Figure E-1 shows a representation of how thermal EMFs are generated. The test leads are made of the A material, while the source under test is the B material. The temperatures between the junctions are shown as T and T .
Page 433: Minimizing Thermal Emfs
Even if all reasonable precautions are taken, some residual thermal offsets may still be present. These offsets can be minimized by using the Model 2701 Relative feature to null them out. To do so, place the instrument on the 3mV range and short the end of the connecting cable nearest the measured source (first disconnect the cable from the source to avoid shorting out the source).
Page 434: Source Resistance Noise
Source resistance noise Noise present in the source resistance is often the limiting factor in the ultimate resolution and accuracy of Model 2701 measurements. The following paragraphs discuss the generation of Johnson noise as well as ways to minimize such noise.
Page 435: Magnetic Fields
Fields can be produced by various sources, such as the AC power line voltage. Large inductors such as power transformers can generate substantial magnetic fields, so care must be taken to keep the Model 2701 voltage source and connecting cables a good distance away from these potential noise sources.
Page 436: Ground Loops
Here, only one instrument is connected to power line ground. Ground loops are not normally a problem with instruments like the Model 2701 that have isolated LO terminals. However, all instruments in the test setup may not be designed in...
Page 437 Measurement Considerations Model 2701 User’s Manual Figure E-3 Eliminating ground loops Instrument 1 Instrument 2 Instrument 3 Power Line Ground...
Page 438: Shielding
Model 2701 User’s Manual Measurement Considerations Shielding WARNING Do not float input LO more than 30V rms, 42.4V peak above earth ground with an exposed shield connected to input LO. To avoid a possible shock hazard, surround the LO shield with a second safety shield that is insulated from the inner shield.
Page 439: Meter Loading
Percent error ------------------ - From the above equation, it is obvious that the input resistance of the Model 2701 must be at least 999 times the value of source resistance if loading error is to be kept to within 0.1%.
Page 440: Temperature Equations
Temperature Equations • Thermocouple equation — Documents the ITS-90 inverse function polynomial and the coefficients to calculate thermocouple temperature. • Thermistor equation — Documents the Steinhart-Hart equation which is used to calculate thermistor temperature. • RTD equation — Documents the Callendar-Van Dusen equation which is used to calculate the temperature vs.
Page 441: Thermocouple Equation
Temperature Equations Model 2701 User’s Manual Thermocouple equation The Model 2701 uses the ITS-90 inverse function coefficients for the polynomial to calculate thermocouple temperature. The Model 2701 measures the thermocouple voltage and then calculates temperature (in °C) as follows: E + c ...
Page 442 Model 2701 User’s Manual Temperature Equations Table F-2 Type E inverse function polynomial -200°C to 0°C 0°C to 1,000°C (-8,825µV to 0µV) (0µV to 76,373µV) 1.697 728 8 × 10 1.705 703 5 × 10 -4.351 497 0 × 10 -2.330 175 9 ×...
Page 443 Temperature Equations Model 2701 User’s Manual Table F-4 Type K inverse function polynomial -200°C to 0°C 0°C to 500°C 500°C to 1,372°C (-5,891µV to 0µV) (0µV to 20,644µV) (20,644µV to 54,886µV) -1.318 058 × 10 2.517 346 2 × 10 2.508 355 2 ×...
Page 444 Model 2701 User’s Manual Temperature Equations Table F-6 Type R inverse function polynomial -50°C to 250°C 250°C to 1,200°C 1,064°C to 1,664.5°C 1,664.5°C to 1,768.1°C (-226µV to 1,923µV) (1,923µV to 13,228µV) (11,361µV to 19,739µV) (19,739µV to 21,103µV) 1.334 584 505 × 10 -8.199 599 416 ×...
Page 445: Thermistor Equation
Selecting a thermistor — The thermistor manufacturers specified curve fitting values (A, B, and C) may not be exactly the same as the ones used by the Model 2701. If they are not exactly the same, perform the following steps to select a thermistor to use with the...
Page 446 Temperature Equations NOTE The specified thermistor temperature measurement accuracy of the Model 2701 (see Appendix A) is based on the curve fitting constants listed in Table F-9. If the thermistor manufacturer’s curve fitting constants are not exactly the same as the ones listed in Table F-9, accuracy will be affected.
Page 447: Rtd Equations
Temperature Equations Model 2701 User’s Manual RTD equations The temperature vs. resistance readings listed in the RTD reference tables are calculated using the Callendar-Van Dusen equation. There are two equations based on different temperature ranges. There is an equation for the -200° to 0°C range and one for the 0° to 630°C range.
Page 448 Model 2701 User’s Manual Temperature Equations RTD parameters for equations The RTD parameters for the Callendar-Van Dusen equations are listed in Table F-10. Table F-10 RTD parameters Type Standard Alpha Beta Delta ¾ at 0°C PT100 ITS-90 0.00385055 0.10863 1.49990 100¾...
Page 449 F-10 Temperature Equations Model 2701 User’s Manual Example 2 Calculate the resistance of a D100 RTD at -100°C (T). The following R (Ω at 0°C), alpha, beta, and delta values are used for the D100 RTD (Table F-10): T = -100°C (Ω...
Page 450: G Ke2700 Instrument Driver Examples
KE2700 Instrument Driver Examples...
Page 451 Model 2701 User’s Manual Introduction An IVI style Instrument Driver is provided with the Models 2700, 2701, and 2750. The driver supports programming in LabView, LabWindows CVI, Visual Basic, and C, Test examples provided by the KE2700 Instrument Driver are listed in Table G-1 and Table G-2.
Page 452: Ke2700 Instrument Driver Examples
Use Case 3 — Two scans using 7708 module: • 40 channel DCV (1V range) scan. • 20 channel Ω4 scan: • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Measurement speed (rate) – 0.1 plc.
Page 453 User Setup 1. • 20 channel Ω4 scan. Configuration saved in User Setup 2. • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Setup 1 or Setup 2 recalled to perform scan.
Page 454 Model 2701 User’s Manual KE2700 Instrument Driver Examples Table G-1 (continued) Visual Basic and CVI (C) examples Name Manual Reference Brief Description Advance6 None Use Case 6 — Scan 160 channels using 7703 module (see NOTE): • Type K thermocouple (TC) temperature measurements.
Page 455 KE2700 Instrument Driver Examples Model 2701 User’s Manual Table G-1 (continued) Visual Basic and CVI (C) examples Name Manual Reference Brief Description Advance8 None Use Case 8 — 7706 module in slot 1 and 7702 module in slot 2: • 7706 module: •...
Page 456 Model 2701 User’s Manual KE2700 Instrument Driver Examples Table G-1 (continued) Visual Basic and CVI (C) examples Name Manual Reference Brief Description MultiRange Page 4-5 (Ex. 1 & 2) Demonstrates various range and function settings. Ohmm Page 3-57 (Ex. 2) Demonstrates measuring offset compensated ohms in one-shot trigger mode.
Page 457 Use Case 3 — Two scans using 7708 module: • 40 channel DCV (1V range) scan. • 20 channel Ω4 scan: • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Measurement speed (rate) – 0.1 plc.
Page 458 User Setup 1. • 20 channel Ω4 scan. Configuration saved in User Setup 2. • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Setup 1 or Setup 2 recalled to perform scan.
Page 459 G-10 KE2700 Instrument Driver Examples Model 2701 User’s Manual Table G-1 (continued) Visual Basic and CVI (C) examples Name Manual Reference Brief Description Simple6 None Use Case 6 — Scan 160 channels using 7703 module (see NOTE): • Type K thermocouple (TC) temperature measurements.
Page 460 Model 2701 User’s Manual KE2700 Instrument Driver Examples G-11 Table G-1 (continued) Visual Basic and CVI (C) examples Name Manual Reference Brief Description Simple8 None Use Case 8 — 7706 module in slot 1 and 7702 module in slot 2: •...
Page 461 G-12 KE2700 Instrument Driver Examples Model 2701 User’s Manual LabVIEW examples Table G-2 lists the LabVIEW examples and “Use Cases” that are provided with the KE2700 Instrument Driver. LabVIEW examples are provided in the file: Examples.llb. Use cases are provided in the file: Use Cases.llb. By default, these are installed in the Program Files\National Instruments\LabView X\instr.lib\KE2700 directory.
Page 462 Use Case 3 — Two scans using 7708 module: • 40 channel DCV (1V range) scan. • 20 channel Ω4 scan: • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Measurement speed (rate) – 0.1 plc.
Page 463 Setup 1. • 20 channel Ω4 scan. Configuration saved in User Setup 2. • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Setup 1 or Setup 2 recalled to perform scan.
Page 464 Model 2701 User’s Manual KE2700 Instrument Driver Examples G-15 Table G-2 (continued) LabVIEW examples Manual Name Reference Brief Description Advance6 None Use Case 6 — Scan 160 channels using 7703 module (see NOTE): • Type K thermocouple (TC) temperature measurements.
Page 465 G-16 KE2700 Instrument Driver Examples Model 2701 User’s Manual Table G-2 (continued) LabVIEW examples Manual Name Reference Brief Description Advance8 None Use Case 8 — 7706 module in slot 1 and 7702 module in slot 2: • 7706 module: • Output analog output values to analog output channels.
Page 466 Use Case 3 — Two scans using 7708 module: • 40 channel DCV (1V range) scan. • 20 channel Ω4 scan: • Models 2700 and 2701 – 100Ω range. • Model 2750 – 10Ω range, dry-circuit ohms enabled. • Measurement speed (rate) – 0.1 plc.
Page 467 G-18 KE2700 Instrument Driver Examples Model 2701 User’s Manual Table G-2 (continued) LabVIEW examples Manual Name Reference Brief Description Simple5 None Use Case 5 — 32-channel scan using 7701 module. • Common-side 4-wire ohms measurements (CSIDe mode). • Dry-circuit ohms option for Model 2750.
Page 468 Model 2701 User’s Manual KE2700 Instrument Driver Examples G-19 Table G-2 (continued) LabVIEW examples Manual Name Reference Brief Description Simple7 None Use Case 7 — Ten 40-channel scans using 7702 module: • Channel 1 uses an external reference junction. • Measurement speed (rate) – 1 plc.
Page 469 Index Aperture 4-12 Applications Sorting resistors 9-14 Auto delay settings 8-4 Symbols Auto ranging 4-3, 4-5 SCPI signal oriented measurement Autozero 3-4, 10-2 MEASure:<function>? [<rang>], Average buffer statistic 6-7 [<res>], 13-8 ¾ symbol 5-13 ¾2 and ¾4 connections for front panel inputs Bandwidth 4-10 3-21 Aperture 4-12...
Page 470 Wrap around buffer 6-11 Multiple channel control 2-20 Range 4-4 Ratio and channel average 5-18 Rel 5-4 Cables 1-5 Scanning 7-27 Leakage 3-23 SCPI see FORMat commands, SCPI refer- CARD menu 2-30 ence tables, and SYSTem commands CARD: CONFIG 2-31 Setups 1-26 CARD: VIEW 2-31 Status byte and service request 11-10...
Page 471 Control sources 7-7 Sink mode, controlling external devices External trigger 7-8 Immediate 7-8 Digits 4-6 Timer 7-8 Commands 4-6 Crest factor 3-12 Programming examples 4-7 Current measurements (DCI and ACI) 3-17 Remote programming 4-6 AMPS fuse replacement (front panel Scanning 4-6 AMPS input) 3-19 Setting 4-7 Amps measurement procedure 3-18...
Page 472 High energy circuit safety precautions 3-3 Example 8-11 Hold With BNC connections 8-14 Reading 8-6 Features Idle 7-7, 8-2, 8-16 Model 2701 1-6 IEEE-488 Filter 4-14 Connector 1-14, 10-10 *RST disables filter 4-18 IEEE-488.2 common commands see Common *RST disables filter state to off 4-21...
Page 473 and ACI) Frequency and period see Frequency and LabVIEW examples G-12 period measurements Limits 9-2 One-shot mode 13-7 Basic operation 9-4 Ranges 4-2 Beeper settings 9-4 Resistance see Resistance measurements Commands 9-12 (¾2 and ¾4) 3-20 Default 9-2 Setting speed 4-10 Enabling/disabling 9-4 Temperature see Temperature measure- Programming example 9-14...
Page 474 Remote programming 4-4 Scanning 4-3 Offset-compensated ohms 3-24, 3-25, 3-26, Range, Digits, Rate, Bandwidth, and Filter 4-1 3-28, 3-30, 3-32 Rate 4-8 Enabling/disabling 3-24 Aperture 4-12 Performing measurements 3-25 Bandwidth 4-12 OPEN key 2-12, 2-19 Bandwidth conflict error 4-13 Open thermocouple detector 3-43 Commands 4-11 OPEN: ALL 2-12, 2-19 Programming examples 4-13...
Page 475 Status byte register 11-8 Response messages 10-27 Status register sets 11-2, 11-10 Multiple 10-27 Relative 5-2 Sending 10-27 Basic operation 5-2 Terminator (RMT) 10-27 commands 5-4 RJ-45 connector 10-10 Pressing REL using rel commands 5-6 RS-232 Programming examples 5-6 Connections 10-32 Remote programming 5-4 Connector 1-14 Scanning 5-3...
Page 476 Remote programming 7-26 Speed Remote programming example 7-32 Setting measurement speed 4-10 Reset 7-13 vs. noise characteristics 4-8 Resume scan after power-up 7-21 Standard deviation buffer statistic 6-8 Sequential and non-sequential 7-3 Standard event status 11-11 Simple 1-35, 7-13 Status and error messages C-1 SCPI commands see FORMat commands, SCPI Status byte and service request (SRQ) 11-8 reference tables, SCPI signal oriented...
Page 477 Thermal EMFs 3-15 Minimizing E-4 User setups see Setups Thermistors 3-36 Connections 3-40 Equation F-6 Visual Basic examples G-2 Temperature measurement configuration Voltage measurements (DCV and ACV) 3-8 3-43 Connections 3-8 Thermocouples 3-33 Front panel input 3-8 Color codes 3-40 Model 7700 switching module 3-10 Connections 3-38 DCV input divider 3-8...
Page 478 Keithley Instruments Corporate Headquarters • 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: 440-248-6168 • 1-800-935-5595 • www.tek.com/keithley A G r e a t e r M e a su r e o f C o n f i d e n c e...

Keithley 2701 User Manual

Getting Started

Closing and Opening Switching Module Channels

Basic DMM Operation

Range, Digits, Rate, Bandwidth, and Filter

Relative, Math, Ratio, Channel Average, and Db

Buffer

Scanning

Triggering

Limits and Digital I/O

Remote Operations

Status Structure

Common Commands

SCPI Signal Oriented Measurement Commands

Format and Miscellaneous System Commands

SCPI Reference Tables

Model 7700 Connection Guide

Quick Links

Related Manuals for Keithley 2701

Summary of Contents for Keithley 2701