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Keithley 2701 Service Manual

Ethernet-based dmm / data acquisition system
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Model 2701
Ethernet-Based DMM / Data Acquisition System
Service Manual
A G R E A T E R M E A S U R E O F C O N F I D E N C E

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Summary of Contents for Keithley 2701

  • Page 1 Model 2701 Ethernet-Based DMM / Data Acquisition System Service Manual A G R E A T E R M E A S U R E O F C O N F I D E N C E...
  • Page 2 WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 3 years from date of shipment. Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation.

  • Page 3: Service Manual

    Model 2701 Ethernet-Based DMM / Data Acquisition System Service Manual ©2002, Keithley Instruments, Inc. All rights reserved. Cleveland, Ohio, U.S.A. First Printing, June 2002 Document Number: 2701-902-01 Rev. A...
  • Page 4 Revision includes a revised copy of this print history page. Revision A (Document Number 2701-902-01) ..............June 2002 All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc. Other brand names are trademarks or registered trademarks of their respective holders.
  • Page 5 Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation Category II, as described in the International Electrotechnical Commission (IEC) Standard IEC 60664. Most measurement, control, and data I/O signals are Installation Category I and must not be directly connected to mains voltage or to voltage sources with high tran- sient over-voltages.
  • Page 6 To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer, test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety ap- provals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from other suppliers as long as they are equivalent to the original component.

  • Page 7: Table Of Contents

    Calculating resistance reading limits ........Restoring factory defaults ............Performing the verification test procedures ....... Verification test summary ........... Test considerations .............. Model 2701 verification ............. Verifying DC voltage ............Verifying AC voltage ............1-10 Verifying DC current ............1-12 Verifying AC current ............
  • Page 8 Comprehensive calibration ............Calibration cycle ..............Recommended equipment ........... Aborting calibration ............Front panel calibration ............Remote calibration ............2-13 Manufacturing calibration ............2-19 Recommended test equipment .......... 2-19 Calibration card preparation ..........2-19 Unlocking manufacturing calibration ........ 2-19 Measuring function generator signal amplitude ....2-20 Front panel manufacturing calibration ......
  • Page 9 Troubleshooting ............... 4-13 Display board checks ............4-13 Power supply checks ............4-13 Digital circuitry checks ............. 4-14 Analog signal switching states .......... 4-14 Disassembly Introduction ................Handling and cleaning ............... Handling PC boards ............Solder repairs ..............Static sensitive devices ............Assembly drawings ..............
  • Page 10 Optimizing measurement speed ..........DC voltage, DC current, and resistance: ......AC voltage and AC current: ..........Temperature: ............... Calibration Reference Introduction ................Command summary ..............Miscellaneous calibration commands ........:CODE ................:COUNt? ................:INIT ................... :LOCK ................:LOCK? ................:SAVE .................
  • Page 11 Model 7700 calibration commands ......... B-17 :CODE ................B-18 :COUNt? ................B-18 :DATE? ................B-19 :INIT ................B-19 :LOCK ................B-20 :LOCK? ................B-20 :RCOunt ................B-20 :SAVE ................B-21 :STEP0 ................B-21 Remote error reporting ............B-22 Error summary ..............B-22 Error queue ...............
  • Page 12 List of Illustrations Performance Verification Figure 1-1 Connections for Model 2701 DC volts verification ....Figure 1-2 Connections for Model 2701 AC volts verification ....1-10 Figure 1-3 Connections for Model 2701 DC current verification ..1-12 Figure 1-4 Connections for Model 2701 AC current verification ..
  • Page 13 List of Tables Performance Verification Table 1-1 Recommended verification equipment ........Table 1-2 DCV reading limits ..............Table 1-3 ACV reading limits .............. 1-11 Table 1-4 DCI limits ................1-12 Table 1-5 ACI limits ................1-13 Table 1-6 Limits for resistance verification ......... 1-15 Table 1-7 Thermocouple temperature verification reading limits ..
  • Page 14 Table 5-2 Power module wire colors ............Replaceable Parts Table 6-1 Model 2701 motherboard parts list ........Table 6-2 Model 2701 display board parts list ........6-11 Table 6-3 Model 2701 backplane board parts list ........ 6-11 Table 6-4 Model 2701 miscellaneous parts list ........

  • Page 15: Performance Verification

    Performance Verification...

  • Page 16: Introduction

    Performance Verification Model 2701 Service Manual Introduction Use the procedures in this section to verify that Model 2701 Ethernet Multimeter/Data Acquisition System accuracy is within the limits stated in the instrument’s one-year accuracy specifications. You can perform these verification procedures: •...

  • Page 17: Verification Test Requirements

    A relative humidity of less than 80% unless otherwise noted. Warm-up period Allow the Model 2701 to warm up for at least two hours before conducting the verification procedures. If the instrument has been subjected to temperature extremes (those outside the ranges stated above), allow additional time for the instrument’s internal temperature to stabilize.

  • Page 18: Recommended Test Equipment

    Performance Verification Model 2701 Service Manual Recommended test equipment Table 1-1 summarizes recommended verification equipment. You can use alternate equipment as long as that equipment has specifications at least as good as those listed in Table 1-1. Keep in mind, however, that calibrator uncertainty will add to the uncertainty of each measurement.

  • Page 19: Verification Limits

    The following is an example of how reading limits have been calculated. Assume you are testing the 10V DC range using a 10V input value. Using the Model 2701 one-year accuracy specification for 10V DC of ± (30ppm of reading + 5ppm of range), the calculated limits are: Reading limits = 10V ±...

  • Page 20: Performing The Verification Test Procedures

    Model 2701 Service Manual Performing the verification test procedures Verification test summary Verification tests can be performed either through the Model 2701 front panel terminals or through plug-in modules. This section contains the following procedures: • Model 2701 verification — Use this procedure to test Model 2701 accuracy through the front panel terminals.

  • Page 21: Test Considerations

    Do not use autoranging for any verification tests, because autorange hysteresis may cause the Model 2701 to be on an incorrect range. For each test signal, you must manu- ally set the correct range for the Model 2701 using the range keys.

  • Page 22: Model 2701 Verification

    Do not exceed 1000V peak between front terminals INPUT HI and INPUT LO because instrument damage may occur. Follow these steps to verify DC voltage accuracy: Connect the Model 2701 HI and LO INPUT jacks to the DC voltage calibrator as shown in Figure 1-1.

  • Page 23: Table 1-2 Dcv Reading Limits

    Model 2701 Service Manual Performance Verification Select the DC volts function by pressing the DCV key and set the Model 2701 to the 100mV range. Set the calibrator output to 0.00000mV DC and allow the reading to settle. Enable the Model 2701 REL mode. Leave REL enabled for the remainder of the DC volts verification tests.

  • Page 24: Verifying Ac Voltage

    V•Hz input, because instrument damage may occur. Follow these steps to verify AC voltage accuracy: Connect the Model 2701 HI and LO INPUT jacks to the AC voltage calibrator as shown Figure 1-2. Be sure the INPUTS switch is in the FRONT position.

  • Page 25: Table 1-3 Acv Reading Limits

    1-11 Select the AC volts function by pressing the ACV key. Set the Model 2701 for the 100mV range; make sure that REL is disabled. Source 1kHz and 50kHz AC voltages for each of the ranges summarized in Table 1-3 and make sure that the respective Model 2701 readings fall within stated limits.

  • Page 26: Verifying Dc Current

    Verifying DC current Check DC current accuracy by applying accurate DC currents from the DC current calibra- tor to the AMPS input of the Model 2701 and verifying that the displayed readings fall within specified limits. Follow these steps to verify DC current accuracy:...

  • Page 27: Verifying Ac Current

    Verifying AC current Check AC current accuracy by applying accurate AC voltage current at specific frequencies from the AC current calibrator to the Model 2701 input, verifying that the displayed readings fall within specified limits. Follow these steps to verify AC current.

  • Page 28: Verifying Resistance

    Select the Model 2701 4-wire resistance function by pressing the Ω4 key, then choose the SLOW integration rate with the RATE key. Set the Model 2701 for the 100Ω range and make sure the FILTER is on. Enable OCOMP (offset-compensated ohms) for 100Ω range verification. (Press SHIFT then OCOMP.)

  • Page 29: Table 1-6 Limits For Resistance Verification

    __________ to __________ MΩ 100MΩ 100MΩ 99.7970 to 100.2030MΩ __________ to __________ MΩ * Enable O COMP (offset-compensated ohms) when testing 100Ω range. ** Calculate limits based on actual calibration resistance values and Model 2701 one-year resistance accuracy specifications. See Verification limits.

  • Page 30: Verifying Temperature

    Figure 1-1.) Be sure the INPUTS switch is in the FRONT position. Configure the Model 2701 for °C units, type J temperature sensor, and 0°C simulated reference junction as follows: Press SHIFT then SENSOR and note the unit displays the temperature units: UNITS: C.
  • Page 31 Be sure the INPUTS switch is in the FRONT position. Configure the Model 2701 temperature function for °C units and RTD temperature sensor (α=0.00385) as follows: Press SHIFT then SENSOR and note the unit displays the temperature units: UNITS: C.

  • Page 32: Verifying Frequency

    Although the following tests are based on the Model 7700 20-Channel Multiplexer, the same general procedures can be used for other plug-in modules that have similar capabilities. Refer to the Model 2701 User’s Manual for specific information on ter- minals and connections for other plug-in modules.

  • Page 33: Figure 1-8 Connections For Model 7700 Dc Volts Verification

    Model 7700 for 100mV and 1V ranges. Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 34: Verifying Ac Voltage

    1-20 Performance Verification Model 2701 Service Manual Verifying AC voltage Check AC voltage accuracy by applying accurate AC voltages at specific frequencies from the AC voltage calibrator to the Model 7700 inputs and verifying that the displayed readings fall within specified ranges.

  • Page 35: Table 1-10 Plug-In Module Acv Reading Limits

    Performance Verification 1-21 Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 36: Verifying Dc Current

    1-22 Performance Verification Model 2701 Service Manual Verifying DC current Check DC current accuracy by applying accurate DC currents from the DC current calibra- tor to the input terminals of the Model 7700 and verifying that the displayed readings fall within specified limits.

  • Page 37: Table 1-11 Plug-In Module Dci Limits

    Performance Verification 1-23 Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 38: Figure 1-11 Connections For Model 7700 Ac Current Verification

    CH11 CH12 CH13 CH14 CH15 CH16 CH21 Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 39: Verifying Resistance

    Model 2701 Service Manual Performance Verification 1-25 Verifying resistance Check resistance by connecting accurate resistance values to the Model 7700 and verifying that its resistance readings are within the specified limits. CAUTION Do not apply more than 300V between plug-in module INPUT or SENSE H and L terminal, or between any adjacent channels, or instrument dam- age could occur.

  • Page 40: Table 1-13 Limits For Plug-In Module Resistance Verification

    Performance Verification Model 2701 Service Manual Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.
  • Page 41 Figure 1-13. Disable external sense on the calibrator. Set the Model 2701 for the 100MΩ range. Source a nominal 100MΩ resistance value and verify that the reading is within calcu- lated limits for the 100MΩ range. Press the OPEN key to open Channel 1.

  • Page 42: Verifying Temperature

    Figure 1-14. Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 43: Table 1-14 Model 7700 Thermocouple Temperature Verification Reading Limits

    Model 2701 Service Manual Performance Verification 1-29 Figure 1-14 Connections for Model 7700 thermocouple temperature verification Twisted Thermocouple Wire Calibrator (Output DC Voltage) INPUT SENSE CH1 H L H L H L H L H L H L H L H L...
  • Page 44 Figure 1-12 similar connecting scheme.) Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 45: Verifying Frequency

    Figure 1-15.) Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for one hour before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 46: Verifying Ratio And Average

    Figure 1-16. Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS switch is set to the REAR position.

  • Page 47: Calibration

    Calibration...

  • Page 48: Introduction

    A relative humidity of less than 80% unless otherwise noted. Warm-up period Allow the Model 2701 Ethernet Multimeter/Data Acquisition system to warm up for at least two hours before performing calibration. If the instrument has been subjected to temperature extremes (those outside the ranges stated above), allow extra time for the instrument’s internal temperature to stabilize.

  • Page 49: Calibration Considerations

    • Always let the source signal settle before calibrating each point. • If an error occurs during calibration, the Model 2701 will generate an appropriate error message. See Appendix B for more information. WARNING Observe the following safety precautions when performing these tests: •...

  • Page 50: Calibration Code

    Confirm the code by pressing ENTER. The Model 2701 allows you to define a new calibration code. Use the up and down range keys to toggle between yes and no. Choose N if you do not want to change the code.

  • Page 51: Comprehensive Calibration

    Model 2701 Service Manual Calibration Comprehensive calibration The comprehensive calibration procedure calibrates the DCV, DCI, ACV, ACI, and ohms functions. You can also choose to calibrate only the DCV/DCI and resistance or ACV/ACI functions. These procedures are usually the only calibration required in the field. Manufacturing cali- bration is normally done only at the factory, but it should also be done in the field if the unit has...

  • Page 52: Aborting Calibration

    Setting calibration dates and saving calibration Preparing the Model 2701 for calibration Turn on the Model 2701 and allow it to warm up for at least two hours before perform- ing a calibration procedure. Start the calibration process as follows: Access the calibration menu by pressing SHIFT then TEST, then display TEST: CALIB using the up or down range key.

  • Page 53: Figure 2-1 Low Thermal Short Connections

    AC voltage and AC current calibration Front panel short and open calibration At the Model 2701 prompt for a front panel short, perform the following: Connect the Model 8610 low-thermal short to the instrument front panel INPUT and SENSE terminals as shown in Figure 2-1.

  • Page 54: Figure 2-2 Connections For Dc Volts And Ohms Calibration

    Set the calibrator to the indicated value and make sure it is in OPERATE. • Press the ENTER key to calibrate that step. • Wait until the Model 2701 finishes each step. (The unit will display the CALIBRATING message while calibrating.)

  • Page 55: Table 2-3 Dc Volts Calibration Summary

    If your calibrator cannot output the values recommended in Table 2-3, use the left and right arrow keys and the up and down range keys to set the Model 2701 display value to match the calibrator output voltage. Table 2-3...

  • Page 56: Figure 2-3 Connections For Dc And Ac Amps Calibration

    After the 1MΩ resistance point has been calibrated, the unit will prompt you to apply 10mA. Follow these steps for DC current calibration: Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3.

  • Page 57: Figure 2-4 Connections For Ac Volts Calibration

    Model 2701 Service Manual Calibration 2-11 AC voltage calibration Follow these steps for AC voltage calibration: Connect the calibrator to the Model 2701 INPUT HI and LO terminals as shown in Figure 2-4. Figure 2-4 Connections for AC volts calibration...

  • Page 58: Table 2-7 Ac Current Calibration Summary

    After the 700VAC at 1kHz point has been calibrated, the unit will prompt you for 100mA at 1kHz. Follow these steps for AC current calibration: Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3.

  • Page 59: Remote Calibration

    RS-232 port using a straight-through 9-pin to 9-pin cable (use a 9-25-pin adapter if necessary). Turn on the Model 2701 and allow it to warm up for at least two hours before performing calibration. Unlock the calibration function by sending this command: :CAL:PROT:CODE 'KI002701' (The above command shows the default code, KI002701.
  • Page 60 Keep drafts away from low-thermal connections to avoid thermal drift, which could affect calibration accuracy. Send the following command: :CAL:PROT:DC:STEP1 After the Model 2701 completes this step, remove the low-thermal short and then send this command: :CAL:PROT:DC:STEP2 NOTE Be sure to minimize movement near front Input terminals. Excessive movements can cause capacitive coupling errors, which could affect calibration accuracy.

  • Page 61: Table 2-8 Dc Voltage Calibration Programming Steps

    • Send the indicated programming command. (Change the command parameter if you are using a different calibration resistance than that shown.) • Wait until the Model 2701 completes each step before continuing. Table 2-9 Resistance calibration programming steps Calibration Calibrator...

  • Page 62: Table 2-10 Dc Current Calibration Programming Steps

    Model 2701 Service Manual DC current calibration After the 1MΩ resistance point has been calibrated, follow these steps for DC current calibration: Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3.

  • Page 63: Table 2-11 Ac Voltage Calibration Programming Steps

    Model 2701 Service Manual Calibration 2-17 AC voltage calibration Follow these steps for AC voltage calibration: Connect the calibrator to the Model 2701 INPUT HI and LO terminals as shown in Figure 2-4. Perform the calibration steps summarized in Table 2-11.

  • Page 64: Table 2-12 Ac Current Calibration Programming Steps

    Calibration Model 2701 Service Manual AC current calibration Follow these steps for AC current calibration: Connect the calibrator to the AMPS and INPUT LO terminals of the Model 2701 as shown in Figure 2-3. Perform the calibration steps summarized in Table 2-12.

  • Page 65: Manufacturing Calibration

    Recommended equipment for manufacturing calibration Stanford Research Systems DS345 Function Generator: 1V RMS, 3Hz, ±5ppm 1V RMS, 1kHz, ±5ppm Keithley Model 2001 or 2002 Digital Multimeter: 1V, 3Hz AC, ±0.13% Keithley 7797 Calibration System Calibration card preparation Before performing manufacturing calibration, short the HI, LO, SHI, and SLO terminals of TE100 on the Model 7797 Calibration System card together using the supplied jumpers.

  • Page 66: Measuring Function Generator Signal Amplitude

    Perform the entire front panel comprehensive calibration procedure discussed earlier in this section. (See “Comprehensive calibration” earlier in this section.) Connect the function generator to the Model 2701 front panel INPUT jacks as shown in Figure 2-5. Select the front input jacks with the INPUTS switch.

  • Page 67: Remote Manufacturing Calibration

    Perform the entire remote comprehensive calibration procedure discussed earlier in this section. (See “Comprehensive calibration” on page 2-5.) Connect the function generator to the Model 2701 INPUT jacks as shown in Figure 2-5. Select the front input jacks with the INPUTS switch.

  • Page 68: Model 7700 Calibration

    The Model 7700 being calibrated should be connected to the Model 7797 Calibration System card and the card should then be installed in scanner Slot #1. (See the Model 7797 documentation.) Note that the module being calibrated will be external to the Model 2701 to avoid card heating during calibration.
  • Page 69 Accurately measure and record the cold temperature of the Model 7700 card surface at the center of the card. Press and hold the Model 2701 OPEN key while turning on the power. Enable calibration by sending the :CODE command. For example, the default...

  • Page 70: Routine Maintenance

    Routine Maintenance...

  • Page 71: Introduction

    The information in this section deals with routine type maintenance and includes procedures for setting the line voltage, replacing the Model 2701 line and front terminal AMPS fuses, and replacing the amps fuses for the Model 7700 plug-in module. Replacement of the Model 2701 non-volatile RAM battery and module relay closure count is also covered.

  • Page 72: Figure 3-1 Power Module

    Model 2701 Service Manual Routine Maintenance Figure 3-1 Power module Model 2701 WARNING: NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY. 10bT 100bT CAT I MADE IN U.S.A. ETHERNET 10/100 BaseT DIGITAL I/O TRIG. LINK RS232 (EXT. TRIG.) KEITHLEY...

  • Page 73: Replacing The Front Terminal Amps Fuse

    Routine Maintenance Model 2701 Service Manual Replacing the front terminal AMPS fuse The front terminal AMPS fuse protects the Model 2701 current input from an over-current condition. Follow the steps below to replace the AMPS fuse. WARNING Make sure the instrument is disconnected from the power line and other equipment before replacing the AMPS fuse.

  • Page 74: Replacing Model 7700 Plug-In Module Amps Fuses

    De-solder the blown CH21 or CH22 fuse as required, taking care not to damage the cir- cuit board or spread solder flux around the board. Install a new 3A, 250V fast-blow fuse, Keithley part number FU-107-1. CAUTION Do not use a fuse with a higher current rating than specified or module damage may occur.

  • Page 75: Replacing Non-Volatile Ram Battery

    Re-install the circuit board into the plastic housing, then close the top cover. Replacing non-volatile RAM battery The Model 2701 has a rechargeable lithium ion battery for non-volatile RAM. Use the pro- cedure below to replace the battery, if required. Refer to the disassembly procedures in...

  • Page 76: Plug-In Module Relay Closure Count

    Routine Maintenance Plug-in module relay closure count The Model 2701 keeps an internal count of the number of times each module relay has been closed. This count will help you determine if and when any relays require replacement (see module contact life specifications). The count can be read or reset only via remote as outlined below.

  • Page 77: Resetting Relay Closure Count

    Resetting relay closure count NOTE The Model 2701 must be in the manufacturing calibration mode to reset the closure count. To do so, press and hold the OPEN key while turning on the power, then send the :CAL:PROT:CODE “code” to unlock calibration (default code: KI002701).

  • Page 78: Troubleshooting

    Troubleshooting...

  • Page 79: Introduction

    Model 2701 Service Manual Introduction This section of the manual will assist you in troubleshooting and repairing the Model 2701. Included are self-tests, test procedures, troubleshooting tables, and circuit descriptions. It is left to the discretion of the repair technician to select the appropriate tests and documentation needed to troubleshoot the instrument.

  • Page 80: Power-On Self-Tests

    Troubleshooting Power-on self-tests RAM and EPROM tests During the power-on sequence, the Model 2701 will perform a checksum test on its EPROM and test its RAM. If the RAM tests fails, the instrument will lock up. Flash memory tests After the RAM and EPROM tests, the instrument will perform a checksum test on flash memory.

  • Page 81: Front Panel Tests

    Troubleshooting Model 2701 Service Manual Front panel tests There are two front panel tests: one to test the functionality of the front panel keys and one to test the display. In the event of a test failure, refer to “Display board checks” on page 4-13 for details on troubleshooting the display board.

  • Page 82: Principles Of Operation

    Model 2701 Service Manual Troubleshooting Principles of operation The following information is provided to support the troubleshooting tests and procedures covered in this section of the manual. Refer to the following block diagrams: Figure 4-1 — Power supply block diagram Figure 4-2—...

  • Page 83: Display Board

    Troubleshooting Model 2701 Service Manual AC power is applied to the AC power module receptacle. Power is routed through the line fuse and line voltage selection switch of the power module to the power transformer. The power transformer has a total of four secondary windings for the various supplies.

  • Page 84: Figure 4-2 Digital Circuitry Block Diagram

    Model 2701 Service Manual Troubleshooting Figure 4-2 Digital circuitry block diagram Li Ion Battery Battery Control/ Charger U4, U16 Flash Real Time SDRAM Memory Clock Keypad XADTX ADTX XADCLK Analog Main Processor ADCLK Display Board Circuitry MCF5407 Display XADTS Controller...

  • Page 85: Digital Circuitry

    Troubleshooting Model 2701 Service Manual Display DS401 is the display module, which can display up to 12 alpha-numeric characters and includes the various annunciators. The display uses a common multiplexing scheme with each character refreshed in sequence. U402 and U403 are the drivers for the display characters and annunciators. Note that data for the drivers are serially transmitted from the microcontroller (MOSI and PC1).

  • Page 86: Rs-232 Interface

    Model 2701 Service Manual Troubleshooting RS-232 interface Serial data transmission and reception is performed by the TXD and RXD lines of the MPU. U15 provides the necessary voltage level conversion for the RS-232 interface port. Trigger circuits Buffering for Trigger Link input and output is performed by U14 and U20. Trigger input and output is controlled by FPGA U9 under MPU supervision.

  • Page 87: Analog Circuitry

    4-10 Troubleshooting Model 2701 Service Manual Analog circuitry Refer to Figure 4-3 for the following discussion on analog circuitry. INPUT HI INPUT HI protection is provided by the SSP (Solid State Protection) circuit. The SSP is primarily made up of Q101 and Q102. An overload condition opens Q101 and Q102, which disconnects the analog input signal from the rest of the analog circuit.

  • Page 88: Figure 4-3 Analog Circuitry Block Diagram

    Model 2701 Service Manual Troubleshooting 4-11 Figure 4-3 Analog circuitry block diagram Front Terminals S101 AMPS Scanner Outputs Current Shunts K103, R158, R205, R338 AC Switching & Gain K102, U102, U103, U105, Front Terminals U112, U118, U111, U110 S101 ACV,...

  • Page 89: Figure 4-4 Ohms Open-Lead Sense Detection Block Diagram

    4-12 Troubleshooting Model 2701 Service Manual Ohms open-lead sense detection There are two types of open sense lead detect (Figure 4-4). The first is for the INPUT HI and INPUT LO leads. For these leads, the open sense detection is implemented in hardware. A comparator circuit monitors the voltage at the INPUT HI lead output and will trip the OVLD detect circuit when the voltage level exceeds an appropriate value for the particular range.

  • Page 90: Troubleshooting

    Model 2701 Service Manual Troubleshooting 4-13 Troubleshooting Troubleshooting information for the various circuits is summarized below. See “Principles of operation” on page 4-5 for circuit theory. Display board checks If the front panel DISP tests show a failure, troubleshoot the display board using Table 4-3.

  • Page 91: Digital Circuitry Checks

    4-14 Troubleshooting Model 2701 Service Manual Digital circuitry checks Digital circuit problems can be checked using Table 4-5. Table 4-5 Digital circuitry checks Step Item/component Required condition Remarks Power-on test RAM OK, ROM OK. Verify that RAM and ROM are functional.

  • Page 92: Table 4-8

    Model 2701 Service Manual Troubleshooting 4-15 Table 4-7 ACV and FREQ signal switching U103 U103 U105 U105 U103 U103 U105 U111 Range Q101 Q102 K101* K102* pin 8 pin 9 pin 9 pin 8 pin 16 pin 1 pin 1...

  • Page 93: Table 4-10

    4-16 Troubleshooting Model 2701 Service Manual Table 4-9 Ω4 signal switching Range Q101 Q102 Q114 Q136 Q109 K101* Q113 Q105 Q104 Q108 100Ω 1kΩ 10kΩ 100kΩ 1MΩ 10MΩ 100MΩ * K101 set states: Pin 8 switched to Pin 7 Pin 3 switched to Pin 4 Table 4-10 Ω2/Ω4 reference switching...

  • Page 94: Table 4-13 Dcv Signal Multiplexing And Gain

    Model 2701 Service Manual Troubleshooting 4-17 Table 4-12 ACA signal switching U105 U105 U111 U105 U103 U103 Range K103* pin 16 pin 1 pin 16 pin 8 pin 16 pin 1 Reset Reset * K103 set states: Pin 8 to 7...

  • Page 95: Table 4-16 Ω2 Signal Multiplexing And Gain

    4-18 Troubleshooting Model 2701 Service Manual Table 4-15 DCA signal multiplexing and gain Signal U129 U129 U129 Gain Range (U163) pin 1 pin 8 pin 9 (U166) ×100 20mA ×100 100mA ×100 ×10 Table 4-16 Ω2 signal multiplexing and gain...

  • Page 96: Table 4-18 Switching Device Locations

    Model 2701 Service Manual Troubleshooting 4-19 Figure 4-3 provides a block diagram of the analog circuitry. Table 4-18 shows where the various switching devices are located in the block diagram. Table 4-18 Switching device locations Switching devices Analog circuit section (see...

  • Page 97: Disassembly

    Disassembly...

  • Page 98: Introduction

    Disassembly Model 2701 Service Manual Introduction This section explains how to handle, clean, and disassemble the Model 2701 Ethernet Multimeter/Data Acquisition System. Disassembly drawings are located at the end of this section. Handling and cleaning To avoid contaminating PC board traces with body oil or other foreign matter, avoid touching the PC board traces while you are repairing the instrument.

  • Page 99: Static Sensitive Devices

    Use the following assembly drawings to assist you as you disassemble and reassemble the Model 2701. Also, refer to these drawings for information about the Keithley part numbers of most mechanical parts in the unit. The drawings are located at the end of this section.

  • Page 100: Disassembly Procedures

    Disassembly Model 2701 Service Manual Disassembly procedures Case cover removal Follow the steps below to remove the case cover to gain access to internal parts. WARNING Before removing the case cover, disconnect the line cord and any test leads from the instrument.

  • Page 101: Card Cage Removal

    Model 2701 Service Manual Disassembly Remove all the connections except the front AMPS connection by pulling the wires off the pin connectors. To remove the front panel AMPS input wire (white), first remove the AMPS fuse holder, then use needle-nose pliers to grasp the AMPS wire near the fuse housing.

  • Page 102: Removing Power Components

    Disassembly Model 2701 Service Manual Using a thin-bladed screwdriver, pry the plastic PC board stop (located at the bottom of the display board) until the bar separates from the casing. Pull the display board from the front panel. Remove the switch pad by pulling it from the front panel.

  • Page 103: Instrument Reassembly

    Yellow SENSE LO Gray AMPS White Power module wire connections Use the information in Table 5-2 and DETAIL B of drawing 2701-050 to connect power module wires. Table 5-2 Power module wire colors Location Wire color Right side Gray Right top...

  • Page 111: Replaceable Parts

    Replaceable Parts...

  • Page 112: Introduction

    Component designation (if applicable) • Keithley part number Factory service If the instrument is to be returned to Keithley Instruments for repair, perform the following: • Call the Repair Department at 1-888-KEITHLEY for a Return Material Authorization (RMA) number. •...

  • Page 113: Table 4-6 Table

    Model 2701 Service Manual Replaceable Parts Table 6-1 Model 2701 motherboard parts list Circuit designation Description Keithley part no. C1,C3,C6,C8,C10,C11,C13,C14,C16-C25,C27 CAP, .1UF, 20%, 50V, CERAMIC C-418-.1 C102 CAP, .01UF, 10%, 1000V, CERAMIC C-64-.01 C103,C111,C191,C196,C256,C257,C263,C269 CAP, .1UF, 20%, 50V, CERAMIC C-418-.1...
  • Page 114 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. C244,C267,C282 CAP, 1000pF, 20%, 50V, CERAMIC C-418-1000P C252,C253 CAP, 22PF, 10%, 100V, CERAMIC C-451-22P C255 CAP, 100UF, 20%, 100V C-573-100...
  • Page 115 Model 2701 Service Manual Replaceable Parts Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. CONN, RT ANGLE, FEMALE, 9 PIN CS-761-9 CONN, D-SUB MALE, BOARDLOCK TYPE CS-848-9 LATCHING HEADER, 5-PIN CS-724-5 CONN, BERG CS-339...
  • Page 116 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. R119,R384,R385 RES, 15K, 1%, 1/4W, METAL FILM R-391-15K R123 RES, 73.2K, 1%, 100MW, THICK FILM R-418-73.2K R126,R128,R185,R275 RES, 475, 1%, 1/4W, METAL FILM...
  • Page 117 Model 2701 Service Manual Replaceable Parts Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. R215,R216 RES, 4.42K, 1%, 1/4W, METAL FILM R-391-4.42K R221,R222 RES, 2.21K, 1%, 1/4W, METAL FILM R-391-2.21K R223 RES, 2.21K, 1%, 1/4W, METAL FILM R-391-2.21K...
  • Page 118 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. R352 RES NET 50K, 1%, .5W, THICK FILM TF-243-50K R353 RESISTOR NETWORK, 10K-10K TF-236 R354 RES NET, 5K, .1%, 668A...
  • Page 119 Model 2701 Service Manual Replaceable Parts Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. U112 IC, LOW COST HIGH SPEED JFET AMP IC-1526 U113,U126 IC, OP-AMP, LTC1050CS8 IC-791 U114,U167 IC, DUAL J-FET OP-AMP, OP-282GS,...
  • Page 120 6-10 Replaceable Parts Model 2701 Service Manual Table 6-1 (Continued) Model 2701 motherboard parts list Circuit designation Description Keithley part no. IC, 2.5V, 1.5A, SWITCHING REGULATOR IC-1505 INTERGRATED CIRCUIT SMT IC-1423 U3,U11 IC, 512K X 32 X 4 BANKS SDRAM...

  • Page 121: Table 4-7 Table

    Model 2701 Service Manual Replaceable Parts 6-11 Table 6-2 Model 2701 display board parts list Circuit designation Description Keithley part no. C401,C402,C411,C403,C404,C405,C407,C409 CAP, .1UF, 20%, 50V, CERAMIC C-418-.1 C406,C408 CAP, 33PF, 10%, 100V, CERAMIC C-451-33P C410,C412 CAP, .1UF, 20%, 50V, CERAMIC C-418-.1...

  • Page 122: Table 6-4 Model 2701 Miscellaneous Parts List

    6-12 Replaceable Parts Model 2701 Service Manual Table 6-4 Model 2701 miscellaneous parts list Quantity Description Keithley part no. SLOT COVER 2750-321A HANDLE 428-329F FN-39-1 SWITCHPAD 2000-310A CHASSIS 2701-301A REAR PANEL 2701-303A FRONT PANEL 2701-308A FRONT PANEL 2001-302H DISPLAY LENS...

  • Page 123: Table 6-5 Model 7700 Parts List

    Model 2701 Service Manual Replaceable Parts 6-13 Table 6-5 Model 7700 parts list Circuit designation Description Keithley part no. C1,C9,C10,C11,C14,C15,C22,C4 CAP, 0.1UF, 20%, 50V, CERAMIC C-418-.1 CAP, 220U, 20%, 10V, TANTALUM C-558-220 C17,C18,C19,C21,C25,C26,C23,C24,C15 CAP, 47P, 5%, 100V, CERAMIC C-465-47P C2,C6,C7,C8,C12,C13,C20,C27,C28,C31 CAP, 0.1UF, 20%, 50V, CERAMIC...
  • Page 124 6-14 Replaceable Parts Model 2701 Service Manual Table 6-5 (Continued) Model 7700 parts list Circuit designation Description Keithley part no. IC, 2.5V, CASCADABLE SERIAL EEPROM LSI-212 IC, QUAD 2 IN AND, 74HCT08 IC-837 IC, 8-CHAN ANA MULTIPLEXER, DG408DY IC-844 U7,U25...

  • Page 131: Specifications

    Specifications...
  • Page 132 2701 Ethernet Multimeter/Data Acquisition System DC CHARACTERISTICS CONDITIONS: MED (1 PLC) or 10 PLC or MED (1 PLC) with Digital Filter of 10 ACCURACY: ±(ppm of reading + ppm of range) TEST INPUT (ppm = parts per million) (e.g., 10ppm = 0.001%) CURRENT ±5%...

  • Page 133: Dc Volts

    2701 Ethernet Multimeter/Data Acquisition System DC Notes DC SPEED vs. NOISE REJECTION 1. 20% overrange except on 1000V and 3A. RMS Noise 2. Add the following to “ppm of range” uncertainty; 100mV 15ppm; 1V and 100V 2ppm; 100Ω 30ppm; Rate Filter Readings/s...

  • Page 134: Ac Current

    AC SYSTEM SPEEDS 7, 9,11 ACCESSORIES SUPPLIED: Model 1751 Safety Test Leads, Product Information CD-ROM, Model 2701 Networking Manual, Model 2701 Getting Started Foldout, 3m cross over RANGE CHANGES : 4/s (3/s). ethernet cable. Software CD-ROM with IVI/VISA drivers for VB, VC/C++, LabVIEW, FUNCTION CHANGES : 4/s (3/s).
  • Page 135 7700 20-Channel Differential Multiplexer w/Automatic CJC GENERAL 20 CHANNELS: 20 channels of 2-pole relay input. All channels config- Card Input urable to 4-pole. 2 CHANNELS: 2 channels of current only input. RELAY TYPE: Latching electromechanical. Card Sense ACTUATION TIME: <3ms. Cold junction Ref x3 CAPABILITIES...

  • Page 136: Accuracy Calculations

    Specifications Model 2701 Service Manual 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 137: Calculating Dbm Characteristics Accuracy

    Model 2701 Service Manual Specifications 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 0.998815V. The relationship between voltage and dBm is as follows: ⁄...

  • Page 138: Calculating Db Characteristics Accuracy

    Specifications Model 2701 Service Manual 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 139: Optimizing Measurement Accuracy

    Model 2701 Service Manual Specifications Optimizing measurement accuracy The configurations listed below assume that the multimeter has had factory setups restored. DC voltage, DC current, and resistance: • Select 6 digits, 10 PLC, filter ON (up to 100 readings), fixed range.

  • Page 140: Calibration Reference

    Calibration Reference...

  • Page 141: Introduction

    Model 2701 Service Manual Introduction This appendix contains detailed information about the various Model 2701 remote calibration commands. Section 2 of this manual covers detailed calibration procedures. For information about additional commands to control other instrument functions, refer to the Model 2701 User’s Manual.
  • Page 142 Model 2701 Service Manual Calibration Reference Table B-1 (Continued) Remote calibration command summary Command Description :CALibration :PROTected :STEP9 <NRf> 1MΩ 4-wire step. :STEP10 <NRf> 10mA DC step. :STEP11 <NRf> 100mA DC step. :STEP12 <NRf> 1A DC step. AC cal steps.

  • Page 143: Miscellaneous Calibration Commands

    Example Send default code of KI002701. :CAL:PROT:CODE 'KI002701' :COUNt? (:CALibration:PROTected:COUNt?) Purpose To determine how many times the Model 2701 has been calibrated. Format :cal:prot:coun? Response <n> Calibration count. Description The :COUNt? command allows you to determine how many times the Model 2701 has been calibrated.

  • Page 144: Init

    Format :cal:prot:init Parameter None Description The :INIT command enables Model 2701 calibration when performing these procedures over the bus. This command must be sent to the unit after sending the :CODE command, but before sending any other calibration command. NOTE The :INIT command should be sent only once before performing either DC, AC, or factory calibration.

  • Page 145: Lock

    :cal:prot:lock? Response Comprehensive calibration locked. Comprehensive calibration unlocked. Description The :LOCK? query requests status from the Model 2701 on calibration locked/unlocked state. Calibration must be enabled sending the :CODE command before calibration can be performed. Example Request cal lock state.

  • Page 146: Date

    Model 2701 Service Manual Calibration Reference :DATE (:CALibration:PROTected:DATE) Purpose To send the calibration date to the instrument. Format :cal:prot:date <year>, <month>, <day> Parameter <year> = 1999 to 2098 <month> = 1 to 12 <day> = 1 to 31 Query format...

  • Page 147: Data

    Calibration Reference Model 2701 Service Manual :DATA? (:CALibration:PROTected:DATA?) Purpose To read calibration constants data. Format :cal:prot:data? Response Floating-point, ASCII values separated by commas. Description The :DATA? query requests all the calibration constants. Values are returned in one string of ASCII floating-point values delimited by commands.

  • Page 148: Dc Calibration Commands

    Model 2701 Service Manual Calibration Reference DC calibration commands The :DC commands perform calibration of the DCV, DCI, and ohms functions. Table B-2 summarizes these calibration commands along with parameter limits. Table B-2 DC calibration commands Command Description Parameter limits...

  • Page 149: Step2

    B-10 Calibration Reference Model 2701 Service Manual :STEP2 (:CALibration:PROTected:DC:STEP2) Purpose To perform front terminal open-circuit calibration. Format :cal:prot:dc:step2 Parameter None Description :STEP2 performs the open-circuit calibration step in the comprehensive calibration procedure. Disconnect all cables and accessories from the input jacks before sending this command.

  • Page 150: Step5

    Model 2701 Service Manual Calibration Reference B-11 :STEP5 (:CALibration:PROTected:DC:STEP5) Purpose To program the 100V DC comprehensive calibration step. Format :cal:prot:dc:step5 <Cal_voltage> Parameter <Cal_voltage> = 90 to 110 [V] Description :STEP5 programs the 100V DC comprehensive calibration step. The allowable range of the calibration voltage parameter is from 90 to 110, but 100 is recommended for best results.

  • Page 151: Step8

    B-12 Calibration Reference Model 2701 Service Manual :STEP8 (:CALibration:PROTected:DC:STEP8) Purpose To program the 100kΩ 4-wire comprehensive calibration step. Format :cal:prot:dc:step8 <Cal_resistance> Parameter <Cal_resistance> = 90E3 to 110E3 [Ω] Description :STEP8 programs the 100kΩ 4-wire resistance comprehensive calibration step. The allowable range of the calibration resistance parameter is from 90E3 to 110E3, but 100E3 is recommended for best results.

  • Page 152: Step11

    Model 2701 Service Manual Calibration Reference B-13 :STEP11 (CALibration:PROTected:DC:STEP11) Purpose To program the 100mA comprehensive calibration step. Format :cal:prot:dc:step11 <Cal_current> Parameter <Cal_current> = 90E-3 to 110E-3 [A] Description :STEP11 programs the 100mA comprehensive calibration step. The allow- able range of the calibration current parameter is from 90E-3 to 110E-3. Use the 100E-3 value whenever possible for best results.

  • Page 153: Ac Calibration Commands

    B-14 Calibration Reference Model 2701 Service Manual AC calibration commands The :AC commands perform comprehensive (user) calibration of the ACV and ACI func- tions. Table B-3 summarizes these calibration commands. Table B-3 AC calibration commands Command Description :CALibration :PROTected :STEP1 10mV AC at 1kHz calibration step.

  • Page 154: Ac:step

    Model 2701 Service Manual Calibration Reference B-15 :AC:STEP<n> (CALibration:PROTected:AC:STEP<n>) Purpose To program individual AC calibration steps. Format :cal:prot:ac:step<n> Parameter 10mV AC at 1kHz calibration step. 100mV AC at 1kHZ calibration step. 100mV AC at 50kHz calibration step. 1V AC at 1kHz calibration step.

  • Page 155: Manufacturing Calibration Commands

    B-16 Calibration Reference Model 2701 Service Manual Manufacturing calibration commands Three calibration steps are only performed at the factory or when the unit has been repaired: 1V AC at 3Hz :CALibration:PROTected:AC:STEP14 1V AC at 1kHz :CALibration:PROTected:AC:STEP15 Rear scanner terminal short circuit :CALibration:PROTected:DC:STEP0 :AC:STEP<14|15>...

  • Page 156: Model 7700 Calibration Commands

    Model 2701 Service Manual Calibration Reference B-17 Model 7700 calibration commands Table B-4 summarizes calibration commands for the Model 7700 plug-in module. Note that CARD1 commands calibrate the card in Slot 1, while CARD2 commands request calibration count and date information from a card in Slot 2.

  • Page 157: Code

    Up to a 8-character string including letters and numbers. Description The :CODE command enables the Model 2701 calibration procedures when performing these procedures over the bus. This command must be sent to the unit before sending any other Model 7700 calibration command. The default calibration code is KI002701.

  • Page 158: Date

    The :CARD1:DATE? and :CARD2:DATE? queries allow you to read back the calibration date from a Model 7700 in Slot 1 and Slot 2, respectively. NOTE The card calibration date is automatically set to the Model 2701 real time clock date when the card is calibrated. Example Request card 1 cal date.

  • Page 159: Lock

    Response Calibration locked. Calibration unlocked. Description The :LOCK? query requests status from the Model 2701 on Model 7700 calibration locked/unlocked state. Calibration must be enabled sending the :CODE command before calibration can be performed. Example Request card 1 cal lock state.

  • Page 160: Save

    Model 2701 Service Manual Calibration Reference B-21 :SAVE (:CALibration:PROTected:CARD1:SAVE) Purpose To save calibration constants in card EEROM after the calibration procedure. Format :cal:prot:card1:save Parameter None Description The :SAVE command stores calculated calibration constants derived during Model 7700 calibration in card EEROM. (EEROM is non-volatile memory.) Calibration constants will be retained indefinitely once saved.

  • Page 161: Remote Error Reporting

    Model 2701 Service Manual Remote error reporting Methods to detect and determine the nature of calibration errors are discussed in the follow- ing paragraphs. See the Model 2701 User’s Manual for details on status register operation. Error summary Table B-5 summarizes Model 2701 calibration errors.
  • Page 162 Model 2701 Service Manual Calibration Reference B-23 Table B-5 (Continued) Calibration error summary Error number and description +451, "1 vac dac error" +452, "10 vac dac error" +453, "100 vac dac error" +454, "100m vac zero error" +455, "100m vac full scale error"...

  • Page 163: Error Queue

    Model 2701 Service Manual Error queue As with other Model 2701 errors, any calibration error will be reported in the remote error queue. You can read this queue by using the :SYST:ERR? query. The Model 2701 will respond with the appropriate error message, as summarized in Table B-5.
  • Page 164 Index Calibration calibration :AC:STEP B-15, B-16 aborting :CODE B-4, B-18 AC current 2-12 :COUNt? B-4, B-18 AC voltage 2-11 :DATE code :DATE? B-19 comprehensive :DC:STEP0 B-16 considerations :INIT B-5, B-19 cycle :LOCK B-5, B-20 DC current 2-10 :LOCK? B-6, B-8, B-20 DC voltage :NDUE front panel...
  • Page 165 Model 2700 resistance verification (100Ω to 10MΩ ranges) 1-14 factory defaults Model 7700 AC current verification 1-24 restoring Model 7700 AC volts verification 1-20 Factory service Model 7700 DC current verification 1-22 frequency Model 7700 DC volts verification 1-19 Verifying, Model 2700 1-18 Model 7700 frequency verification 1-31...
  • Page 166 line fuse Power supply checks 4-13 replacing Power supply components Line power 1-3, 2-2 Power transformer removal line voltage Power-on self-test setting ratio and average Maintenance,Routine verifying, Model 7700 1-32 Manufacturing calibration 2-19 reading limit Extender board preparation 2-19 ACV, Model 2700 1-11 front panel 2-20...
  • Page 167 Specifications verification test Static sensitive devices procedures Status byte EAV (Error Available) bit B-24 Verification test requirements Switching device locations 4-19 verifying AC current, Model 7700 1-24 Temperature Ω2 signal multiplexing and gain temperature 4-18 Ω2 signal switching RTD, Model 2700 1-17 4-15 Ω2/Ω4 reference switching...
  • Page 168 Specifications are subject to change without notice. All Keithley trademarks and trade names are the property of Keithley Instruments, Inc. All other trademarks and trade names are the property of their respective companies. Keithley Instruments, Inc. 28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: 440-248-6168 1-888-KEITHLEY (534-8453) •...

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