Page 1 Title Page UM-23654-Z User’s Manual for Standard TEMPpoint, VOLTpoint, and MEASURpoint USB Instruments DT9871, DT9871U, DT9872, DT9873, DT9874...
Page 2 Copyright Page Trademark and Copyright Information Measurement Computing Corporation, InstaCal, Universal Library, and the Measurement Computing logo are either trademarks or registered trademarks of Measurement Computing Corporation. Refer to the Copyrights & Trademarks section on mccdaq.com/legal for more information about Measurement Computing trademarks. Other product and company names mentioned herein are trademarks or trade names of their respective companies.
Page 3 Changes or modifications to this equipment not expressly approved by Data Translation could void your authority to operate the equipment under Part 15 of the FCC Rules.
Page 5: Table Of Contents
Table of Contents Table of Contents About this Manual ............9 Intended Audience.
Page 6 DT9871 Block Diagram........
Page 7 System Temperature Error for the DT9871 ........
Page 8 Contents Voltage Connectors ............127 External Power Supply Specifications.
Page 9: About This Manual
About this Manual TEMPpoint™ is a family of temperature measurement instruments that includes the DT9871, DT9871U, DT8871, DT8871U, DT9872, and DT8872. This manual describes the DT9871, DT9871U, and DT9872 USB models. VOLTpoint™ is a family of voltage measurement instruments that includes the DT9873 and DT8873.
Page 10: How This Manual Is Organized
About this Manual How this Manual is Organized This manual is organized as follows: • Chapter “Overview,” summarizes the major features of the TEMPpoint, VOLTpoint, and MEASURpoint instruments, as well as the supported software and accessories. • Chapter “Preparing to Use the Instrument,” describes how to unpack the instrument, check the system requirements, install the software, and view the documentation online.
Page 11: Related Information
RTD types, standards, and linearization. Where To Get Help Should you run into problems installing or using a TEMPpoint, VOLTpoint, or MEASURpoint instrument, the Data Translation Technical Support Department is available to provide technical assistance. Refer to Chapter 7 for more information.
Page 12 About this Manual...
Page 13: Chapter 1: Overview
Overview Hardware Features............Supported Software .
Page 14: Hardware Features
Chapter 1 Hardware Features Data Translation provides a number of USB instruments to meet your measurement needs, including the following: • TEMPpoint – a family of temperature measurement instruments • VOLTpoint – a family of voltage measurement instruments • MEASURpoint – a family of mixed temperature and voltage measurement instruments All of these instruments support Version 2.0 and 1.1 of the USB bus.
Page 15  Input range of ±0.075 V for the DT9871U (with 0.25 V RMS A/D noise using no software filtering) and ±1.25 V for the DT9871 (with 5 V RMS A/D noise using no software filtering)  Break-detection circuitry to detect open thermocouple inputs •...
Page 16: Voltpoint Features
Chapter 1 VOLTpoint Features Figure 2 shows a VOLTpoint instrument. Figure 2: VOLTpoint Instrument The key features of VOLTpoint (DT9873) instruments are as follows: • Direct connection of analog input channels for differential voltage inputs; removable screw terminal blocks for each channel for quick wiring •...
Page 17: Measurpoint Features
Overview MEASURpoint Features The standard MEASURpoint (DT9874) instrument provides 16 thermocouple channels, 16 RTD channels, and 16 voltage channels. Figure 3 shows a MEASURpoint instrument. Figure 3: MEASURpoint Instrument The key features of MEASURpoint instruments are as follows: • Analog Input Channels 0 to 15: ...
Page 18 Chapter 1  4-wire, 3-wire, or 2-wire configurations; the DT9872 automatically linearizes the measurements and returns the data as 32-bit, floating-point temperature, resistance, or voltage values  Input range of ±1.25 V • Analog Input Channels 31 to 48:  Direct connection of analog input channels for differential voltage inputs; removable screw terminal blocks for each channel for quick wiring ...
Page 19: Supported Software
• QuickDAQ Base Version – The base version of QuickDAQ is free-of-charge and allows you to acquire and analyze data from all Data Translation USB and Ethernet devices, except the DT9841 Series, DT9817, DT9835, and DT9853/54. Using the base version of QuickDAQ, you can perform the following functions: ...
Page 20 Chapter 1  Supports dB or linear scaling with RMS (root mean squared), peak, and peak-to-peak scaling options  Supports linear or exponential averaging with RMS, vector, and peak hold averaging options.  Supports windowed time channels.  Supports the following response window types: Hanning, Hamming, Bartlett, Blackman, Blackman Harris, and Flat top.
Page 21: Accessories
Overview Accessories The following optional accessories are available for TEMPpoint, VOLTpoint, or MEASURpoint instruments: • STP37 screw terminal panel – The STP37, shown in Figure 4, permits easy screw terminal connections for accessing the digital I/O signals of a TEMPpoint, VOLTpoint, or MEASURpoint instrument.
Page 22: Getting Started Procedure
Chapter 1 Getting Started Procedure The flow diagram shown in Figure 6 illustrates the steps needed to get started using a TEMPpoint, VOLTpoint, or MEASURpoint instrument. This diagram is repeated in each Getting Started chapter; the shaded area in the diagram shows you where you are in the getting started procedure.
Page 23: Part 1: Getting Started
Part 1: Getting Started...
Page 25: Instrument
Preparing to Use the Instrument Unpacking ..............Checking the System Requirements .
Page 26 Chapter 2 Prepare to Use the Instrument (this chapter) Set Up and Install the Instrument (see Chapter 3 starting on page Wire Signals (see Chapter 4 starting on page Verify the Operation of the Instrument (see Chapter 5 starting on page...
Page 27: Unpacking
• For DT9872, DT9874, and DT9874 instruments, a bag of pluggable screw terminable blocks If an item is missing or damaged, contact Data Translation. If you are in the United States, call the Customer Service Department at (508) 946-5100. An application engineer will guide you through the appropriate steps for replacing missing or damaged items.
Page 28: Checking The System Requirements
Chapter 2 Checking the System Requirements For reliable operation, ensure that your computer meets the following system requirements: • Processor: Pentium 4/M or equivalent • RAM: 1 GB • Screen Resolution: 1024 x 768 pixels • Operating System: Windows 8, Windows 7, Windows Vista (32- and 64-bit) Windows XP SP3 (32-bit) •...
Page 29: Installing The Software
Preparing to Use the Instrument Installing the Software Install the software for your instrument from the web at https://www.mccdaq.com/downloads/DTSoftware/MEASURpoint. The installation program guides you through the installation process.
Page 30: Viewing The Documentation
• For documentation about the TEMPpoint, VOLTpoint, or MEASURpoint instrument, click Programs -> Data Translation, Inc -> Hardware Documentation -> User’s Manual for Standard TEMPoint, VOLTpoint, and MEASURpoint USB Instruments. • For documentation on QuickDAQ, click Programs -> Data Translation, Inc ->...
Page 31: Chapter 3: Setting Up And Installing
Setting Up and Installing the Instrument Applying Power ............. . Attaching the Instrument to the Computer .
Page 32 Chapter 3 Prepare to Use the Instrument (see Chapter 2 starting on page Set Up and Install the Instrument (this chapter) Wire Signals (see Chapter 4 starting on page Verify the Operation of the Instrument (see Chapter 5 starting on page Note: Your TEMPpoint, VOLTpoint, and MEASURpoint instruments are factory-calibrated.
Page 33: Applying Power
Setting Up and Installing the Instrument Applying Power TEMPpoint, VOLTpoint, and MEASURpoint instruments are shipped with an EP361 +5V power supply and cable. To apply power to the instrument, do the following: 1. Connect the +5 V power supply to the power connector on the rear panel of the instrument.
Page 34 Chapter 3 Figure 8 shows the location of the Power LED on the front panel of the instrument; a MEASURpoint instrument is shown in this example. Power LED Figure 8: Power LED on the Front Panel of the Instrument...
Page 35: Attaching The Instrument To The Computer
Setting Up and Installing the Instrument Attaching the Instrument to the Computer This section describes how to attach a TEMPpoint, VOLTpoint, or MEASURpoint instrument to the host computer. Notes: Most computers have several USB ports that allow direct connection to USB devices. If your application requires more TEMPpoint, VOLTpoint, or MEASURpoint instruments than you have USB ports for, you can expand the number of USB devices attached to a single USB port by using expansion hubs.
Page 36 Chapter 3 USB port of instrument Attach USB cable to USB port of host computer Figure 9: Attaching the Instrument to the Host Computer 3. Attach the other end of the USB cable to one of the USB ports on the host computer. The operating system automatically detects the instrument and starts the Found New Hardware wizard.
Page 37 Setting Up and Installing the Instrument Note: Windows 7 and Windows 8 find the device automatically. If the power supply and the instrument are attached correctly, the USB LED on the rear panel, shown in Figure 10, turns green. USB LED LMT LED OPN LED Figure 10: LEDs on the Rear Panel of the Instrument...
Page 38: Connecting To An Expansion Hub
Chapter 3 Connecting to an Expansion Hub Expansion hubs are powered by their own external power supply. Theoretically, you can connect up to five expansion hubs to a USB port on the host computer. However, the practical number of instruments that you can connect to a single USB port depends on the throughput you want to achieve.
Page 39 Setting Up and Installing the Instrument +5 V Power Supply +5 V Power Supply TEMPpoint, Cables TEMPpoint, VOLTpoint, or VOLTpoint, or MEASURpoint MEASURpoint Host Computer USB Cable USB Cable Power Supply Expansion Hubs for Hub Power Supply USB Cables for Hub TEMPpoint, TEMPpoint, VOLTpoint, or...
Page 40: Configuring The Device Driver
Chapter 3 Configuring the Device Driver Note: In Windows 7, Windows 8, and Vista, you must have administrator privileges to run the Open Layers Control Panel. When you double-click the Open Layers Control Panel icon, you may see the Program Compatibility Assistant. If you do, select Open the control panel using recommended settings.
Page 41: Chapter 4: Wiring Signals
Wiring Signals General Wiring Recommendations ..........Warm-Up Time .
Page 42 Chapter 4 Prepare to Use the Instrument (see Chapter 2 starting on page Set Up and Install the Instrument (see Chapter 3 starting on page Wire Signals (this chapter) Verify the Operation of the Instrument (see Chapter 5 starting on page...
Page 43: General Wiring Recommendations
Wiring Signals General Wiring Recommendations Keep the following recommendations in mind when wiring signals to a TEMPpoint, VOLTpoint, or MEASURpoint instrument: • Separate power and signal lines by using physically different wiring paths or conduits. • To avoid noise, do not locate the instrument and cabling next to sources that produce high electromagnetic fields, such as large electric motors, power lines, solenoids, and electric arcs, unless the signals are enclosed in a mumetal shield.
Page 44: Warm-Up Time
Chapter 4 Warm-Up Time For accurate thermocouple measurements, MEASURpoint instruments require a warm-up time of 1 hour for the analog circuitry to stabilize. For accurate RTD measurements, ensure that your RTD sensors and external calibration resistors warm up for 1 minute after the MEASURpoint instrument has been warmed up for 1 hour.
Page 45: Connecting Thermocouple Inputs
Wiring Signals Connecting Thermocouple Inputs The DT9871U, DT9871, and DT9874 instruments contain thermocouple jacks for connecting thermocouple inputs. Note: On the standard DT9874 instrument, channels 0 to 15 correspond to the thermocouple input channels. Internally, these signals are connected in differential mode. You can mix and match the following thermocouple types across channels: B, E, J, K, N, R, S, and/or T.
Page 46 Chapter 4 CAUTION: When connecting inputs to the thermocouple connectors on a MEASURpoint or TEMPpoint instrument, it is highly recommended that you use only original Omega thermocouple plugs (SMPW), as connectors from other suppliers may not be equivalent mechanically. Refer to page 126 for more information on the connectors.
Page 47: Connecting Rtd Inputs
Wiring Signals Connecting RTD Inputs Each DT9872 and DT9874 contains pluggable screw terminals for connecting RTD inputs. Internally, these signals are connected in differential mode. Note: On the standard DT9874 instrument, channels 16 to 31 correspond to the RTD input channels.
Page 48: 4-Wire Rtd Connections
Chapter 4 The DT9872 reads this voltage drop and automatically converts the voltage to the appropriate temperature based on the RTD type. The DT9872 and DT9874 support Pt100 (100  Platinum), Pt500 (500  Platinum), and Pt1000 (1000  Platinum) RTD types using Alpha coefficients of 0.00385 and 0.00392; you can mix and match RTD types across RTD channels.
Page 49: 2-Wire Rtd Connections
Wiring Signals RTD Channel  Return Current – Sense +Sense is lead wire resistance. Figure 15: 3-Wire RTD Connection 2-Wire RTD Connections The 2-wire configuration is the least accurate of the RTD wiring configurations because the lead wire resistance (R ) and its variation with temperature contribute significant measurement errors, particularly if the lead wire is long.
Page 50 Chapter 4 RTD Channel  Return Current – Sense +Sense Figure 16: 2-Wire RTD Connection...
Page 51: Connecting Voltage Inputs
Connecting Voltage Inputs to Thermocouple Channels Figure 17 shows how to connect a differential voltage input to a thermocouple input channel on the DT9871U, DT9871, or DT9874 instrument. Note: On the standard DT9874 instrument, channels 0 to 15 correspond to the thermocouple input channels.
Page 52 Chapter 4 Thermocouple Channels Omega Plug (SMPW-U-M) Voltage Input Analog Input 0 Analog Input 0 Return – Signal Source Figure 17: Connecting Voltage Inputs to a Thermocouple Channel...
Page 53: Connecting Voltage Inputs To Rtd Channels
Wiring Signals Connecting Voltage Inputs to RTD Channels Figure 18 shows how to connect a voltage input to an RTD channel on a DT9872 or DT9874 instrument. Note: On the standard DT9874 instrument, channels 16 to 31 correspond to the RTD input channels.
Page 54: Connecting Voltage Inputs To Voltage Channels
Chapter 4 Connecting Voltage Inputs to Voltage Channels Each DT9873 and DT9874 contains pluggable screw terminals for connecting voltage inputs. Note: On the standard DT9874 instrument, channels 32 to 47 correspond to the voltage input channels. Figure 19 shows the numbering of the screw terminal blocks for voltage input connections. Voltage Input Channels Shield...
Page 55 Wiring Signals Figure 20 shows how to connect voltage inputs to the DT9873 and DT9874. Voltage Input Channel – Sense +Sense Shield Vin – Vin + *Pin 2 is no connect Figure 20: Connecting Voltage Inputs The input impedance is well over 100 M using the voltage –Sense and +Sense inputs. Note: For best accuracy when connecting voltage inputs, use twisted-pair wires with a dead-ended shield connected to pin 4 of the screw terminal block.
Page 56: Connecting Current Loop Inputs
±0.75 A. Thermocouple input channels on the DT9871 have an input range of ±1.25 V. Therefore, you can use a 1  series resistor to measure ±1.25 A. Similarly, you can use a 0.1  series resistor to measure ±12.5 A or a 10 ...
Page 57  For thermocouple channels on the DT9871U and DT9874, 1 = 0.075 A = 0.075 V.  For thermocouple channels on the DT9871, 1 = 1.25 A = 1.25 V. Figure 21: Connecting Current Loop Inputs to Thermocouple Channels...
Page 58: Connecting Current Loop Inputs To Rtd Channels
Chapter 4 Connecting Current Loop Inputs to RTD Channels RTD channels on the DT9872 and DT9874 instruments have an input range of ±1.25 V. Therefore, you can use a 1  shunt resistor to measure ±1.25 A. Similarly, you can use a 0.1  shunt resistor to measure ±12.5 A or a 10 ...
Page 59: Connecting Current Loop Inputs To Voltage Channels
Wiring Signals Connecting Current Loop Inputs to Voltage Channels Voltage channels on the DT9873 and DT9874 instruments have an input range of ±10 V or ±60 V. You select the input range for each channel using software. With the 24-bit A/D converter, high current, high side current shunts can be used for resolutions of less than 0.01 A on a 100 A range.
Page 60: Connecting Digital I/O Signals
Chapter 4 Connecting Digital I/O Signals To make digital I/O connections easier, you can use the optional STP37 screw terminal panel and EP333 cable with your TEMPpoint, VOLTpoint, or MEASURpoint instrument. Connect the STP37 to the digital I/O connector of the instrument as shown in Figure Digital I/O Connector...
Page 61: Connecting Digital Input Signals
Wiring Signals Digital Input 1+ Digital Output 7  Digital Output 7 Digital Input 1 1 20 18 19 37 Digital Input 2+ Digital Output 6  Digital Input 2 Digital Output 6 Digital Input 3+ Digital Output 5  Digital Input 3 Digital Output 5 Digital Input 4+...
Page 62: Connecting Digital Output Signals
Chapter 4 Connecting Digital Output Signals The digital output lines of a TEMPpoint, VOLTpoint, or MEASURpoint instrument act as solid-state relays. The customer-supplied signal can be ±30 V at up to 400 mA (peak) AC or You can use the digital output lines of the instrument to control solid-state or mechanical relays or high-current electric motors.
Page 63: Of Your Instrument
Verifying the Operation of Your Instrument Overview ..............Select the Instrument .
Page 64 Chapter 5 Prepare to Use the Instrument (see Chapter 2 starting on page Set Up and Install the Instrument (see Chapter 3 starting on page Wire Signals (see Chapter 4 starting on page Verify the Operation of the Instrument (this chapter)
Page 65: Overview
Verifying the Operation of Your Instrument Overview You can verify the operation of your TEMPpoint, VOLTpoint, or MEASURpoint instrument using the base version of the QuickDAQ application that is provided with the instrument. (Refer to page 29 for information on installing the QuickDAQ application.) This chapter describes how to use QuickDAQ to measure and display temperature and voltage data from a data acquisition device.
Page 66: Select The Instrument
Chapter 5 Select the Instrument To get started with QuickDAQ, follow these steps: 1. Connect your instrument to the USB port of your computer, and connect your sensors to the instrument. 2. Start QuickDAQ. The Device Selection window appears. 3. Select MEASURpoint_USB for the Device Family name. 4.
Page 67 Verifying the Operation of Your Instrument 6. If you want to rename your device, do the following: a. Click the Row Selector button for the device. b. Click the module name in the Name column to highlight it and enter a meaningful name to represent each available device.
Page 68: Configure The Channels
Chapter 5 Configure the Channels Configure the channels as follows: 1. Configure each analog input channel by clicking the Configuration menu, and clicking Input Channel Configuration, or by clicking the Input Channel Configuration toolbar button ( 2. Enable analog input channels 0, 8, and 16 by clicking the checkbox under the Enable column.
Page 69 Verifying the Operation of Your Instrument 5. Under the Engineering Units column, Deg C is selected by default. If you want to change this setting, change the temperature units under the Acquisition Config - Acquisition tab. In this example, Deg C is used. 6.
Page 70: Configure The Parameters Of The Acquisition Config Window
Chapter 5 Configure the Parameters of the Acquisition Config Window For this example, set the Acquisition Config parameters as follows: 1. Click the Recording tab. 2. For Filename generation, select Filename. 3. Enter a meaningful name for the data file. In this example, QuickDAQ Data.hpf is used.
Page 71 Verifying the Operation of Your Instrument 8. For this example, ensure that the following default settings are used:  Sampling Frequency: 10 Hz  Trigger Source: Software  Temperature Unit: Celsius  Filter Type: Moving Average 9. If desired, hide the Acquisition Config window by clicking the Auto-Hide pin ( ) in the top, right corner of the window.
Page 72: Configure The Appearance Of The Channel Display Window
Chapter 5 Configure the Appearance of the Channel Display Window Configure the appearance of the Channel Display window as follows: 1. Ensure that the Visible Display column in the Plot and Data Config window is checked for all three enabled channels. 2.
Page 73: Configure The Appearance Of The Channel Plot Window
Verifying the Operation of Your Instrument Configure the Appearance of the Channel Plot Window Configure the appearance of the Channel Plot window as follows: 1. In the Plot and Data Config window, set up the following parameters: a. Ensure that the Visible Plot column is checked for all three enabled channels. b.
Page 74 Chapter 5 3. Leave the following settings unchanged:  Plot update rate: 1  Smooth scrolling: unchecked  Disable during acquisition: unchecked  Time domain X axis units: Relative time  Display Milliseconds: unchecked  Display Days: unchecked 4. In the display area, click the tab for the Channel Plot window. 5.
Page 75 Verifying the Operation of Your Instrument c. Enter the following text: Voltage Channels The Channel Plot window should appear as follows:...
Page 76: Configure The Appearance Of The Statistics Window
Chapter 5 Configure the Appearance of the Statistics Window Configure the appearance of the Statistics window as follows: 1. Ensure that the Visible Statistics column in the Plot and Data Config window is checked for all three enabled channels: 2. If desired, hide the Plot and Data Config window by clicking the Auto-Hide pin ( ) in the top, right corner of the window.
Page 77: Position The Windows
Verifying the Operation of Your Instrument Position the Windows If you want see the data that is displayed in the Channel Display, Channel Plot, and Statistics windows at once, you need to move the windows to different locations in the display area. In the following example, the Channel Display window is located at the top of the display area, the Channel Plot window is located in the middle of the display area, and the Statistics window is located at the bottom of the display area:...
Page 78 Chapter 5 2. Click the tab for the Channel Plot window, drag the window toward the middle of the display area, move the mouse over the guide on the bottom of the guide diamond, and then release the mouse button. The Channel Plot window is now placed in the middle of the display area, revealing the Channel Display window at the top of the display area.
Page 79: Start The Measurement
Verifying the Operation of Your Instrument Start the Measurement Once you have configured the channels and the display area, start acquisition and log data to disk by clicking the Record toolbar button ( Results similar to the following are displayed in the display area. If desired, you can view the data in Excel by clicking the Open Current Data in Excel toolbar button (...
Page 80 Chapter 5...
Page 81: Part 2: Using Your Instrument
Part 2: Using Your Instrument...
Page 83: Chapter 6: Principles Of Operation
Principles of Operation Block Diagrams............. . . Analog Input Features .
Page 84: Block Diagrams
Chapter 6 Block Diagrams This section includes the block diagrams for the DT9871U, DT9871, and DT9872 TEMPpoint instruments, DT9873 VOLTpoint instrument, and DT9874 MEASURpoint instruments. DT9871U Block Diagram Figure 28 shows the block diagram of the DT9871U TEMPpoint instrument. 1 of 8...
Page 85: Dt9871 Block Diagram
Digital Output 24-Bit Isolators Control FPGA CJC Per Point 1 of up to 48 Channels Power LED USB LED USB 2.0 Processor Limit LED Calibration Open TC LED USB 2.0 ID ROM Figure 29: Block Diagram of the DT9871 TEMPpoint Instrument...
Page 86: Dt9872 Block Diagram
Chapter 6 DT9872 Block Diagram Figure 30 shows the block diagram of the DT9872 TEMPpoint instrument. 1 of 8 64 kB Digital Input +425 A SRAM Isolated Isolators Current Source DC-DC 1 of 8 2.5 Hz Filter Digital Output Isolators 24-Bit Control FPGA...
Page 87: Dt9873 Block Diagram
Principles of Operation DT9873 Block Diagram Figure 31 shows the block diagram of the DT9873 VOLTpoint instrument. 1 of 8 64 kB Digital Input Isolated SRAM Isolators DC-DC 2.5 Hz Filter 1 of 8  24-Bit Digital Output Isolators Control –...
Page 88: Dt9874 Block Diagram
Chapter 6 DT9874 Block Diagram Figure 32 shows the block diagram of the DT9874 MEASURpoint instrument. 1 of 8 64 kB +10 nA Break Digital Input Isolated SRAM Detection Isolators DC-DC 1 of 8 Digital Output 24-Bit Isolators – CJC Per Point Channels 0 to 15 Power LED...
Page 89: Analog Input Features
Analog Input Type Models Channels Channel Types TEMPpoint DT9871U-8 and DT9871-8 8 thermocouple inputs (numbered 0 to 7) DT9871U-16 and DT9871-16 16 thermocouple inputs (numbered 0 to 15) DT9871U-24 and DT9871-24 24 thermocouple inputs (numbered 0 to 23) DT9871U-32 and DT9871-32...
Page 90: Thermocouple Input Channels
Chapter 6 Table 2: Number and Type of Analog Input Channels (cont.) # of Instrument Analog Input Type Models Channels Channel Types VOLTpoint DT9873-8 8 voltage inputs (numbered 0 to 7) DT9873-16 16 voltage inputs (numbered 0 to 15) DT9873-24 24 voltage inputs (numbered 0 to 23) DT9873-32 32 voltage inputs (numbered 0 to 31)
Page 91: Cold Junction Compensation
Open Thermocouple Detection Break detection circuitry (+10 nA on the DT9871U and DT9874; +100 nA on the DT9871) is provided for thermocouple channels to ensure that open thermocouples are detected. The Open (OPN) LED on the rear panel lights when this condition occurs; see Figure 10 on page 37 for the location of this LED.
Page 92: Rtd Channels
Chapter 6 In addition, the software returns the value SENSOR_IS_OPEN (99999 decimal) for any channel that was configured for a thermocouple input and has either an open thermocouple or no thermocouple connected to it. This value is returned anytime a voltage greater than 100 mV is measure on the input, since this value is greater than any legitimate thermocouple voltage.
Page 93: Out Of Range Data For Thermocouple Channels
Table 4: Supported Input Ranges Instrument Type Models Input Range TEMPpoint DT9871U ±0.75 V for all channels DT9871 ±1.25 V for all channels DT9872 ±1.25 V for all channels VOLTpoint DT9873 ±10 V or ±60 V (software-selectable for each channel)
Page 94: Out Of Range Data For Rtd Channels
Chapter 6 Out of Range Data for RTD Channels Each RTD type corresponds to an allowable voltage range. If a voltage is measured on the input that is outside of the legal range for the selected RTD type, the channel may be configured for the wrong type of RTD or something other than an RTD may be connected to the channel.
Page 95: Sample Clock Source
Optionally, you can return your instrument to Data Translation for recalibration. For information on factory recalibration, contact Data Translation at 508-946-5100 (if you are in the USA) or call your local distributor (if you are located outside the USA); see our web site (www.mccdaq.com) for the name and telephone number of your nearest distributor.
Page 96: Conversion Modes
Chapter 6 Conversion Modes TEMPpoint, VOLTpoint, and MEASURpoint instruments support continuous scan conversion modes for reading input measurements. Continuous scan mode takes full advantage of the capabilities of the TEMPpoint, VOLTpoint, and MEASURpoint instruments. Use continuous scan mode if you want to accurately control the period between successive simultaneous conversions of specific channels.
Page 97: Filtering
Principles of Operation The FIFO on the instrument is used as a circular buffer. Acquisition continues indefinitely until you stop the operation. When the FIFO is full, the operation wraps to the beginning of the FIFO; values are overwritten starting at the first location in the FIFO. It is up to your application to retrieve the data from the FIFO;...
Page 98: Data Format For Thermocouple Channels
Chapter 6 Data Format for Thermocouple Channels If you specify a thermocouple type of None for a thermocouple input channel, a voltage measurement is selected and the instrument returns a voltage value. For the DT9871U and DT9874 instruments, the value is in the range of ±0.075 V; for the DT9872 instrument, the value is in the range of ±1.25 V.
Page 99 Principles of Operation Additionally, the following constants may be reported to the host: • 99999.0 – SENSOR_IS_OPEN, described on page 91 • 88888.0 – TEMP_OUT_OF_RANGE_HIGH, described on page 93 page 94 • –88888.0 – TEMP_OUT_OF_RANGE_LOW, described on page 93 page 94 If any of these constants is reported, the A/D subsystem continues to acquire data;...
Page 100: Digital I/O Features
Chapter 6 Digital I/O Features TEMPpoint, VOLTpoint, and MEASURpoint instruments provide 8 digital input lines and 8 digital output lines that you can use to control external equipment, including solid-state or mechanical relays. This section describes the following digital I/O features: •...
Page 101: Digital Output Lines
Principles of Operation Digital Output Lines TEMPpoint, VOLTpoint, and MEASURpoint instruments feature eight, latched and isolated digital output lines. The outputs are solid-state relays that operate at ±30 V and 400 mA peak (AC or DC). Switching time is 2 ms maximum. Figure 35 shows the digital output circuitry.
Page 102 Chapter 6...
Page 103: Chapter 7: Troubleshooting
Troubleshooting General Checklist ............Technical Support .
Page 104: General Checklist
5. Check that you have wired your signals properly using the instructions in Chapter 6. Search the DT Knowledgebase in the Support section of the Data Translation web site (at www.mccdaq.com) for an answer to your problem. If you still experience problems, try using the information in...
Page 105 Calibration Utility, described on page 16, or return your instrument to Data Translation for recalibration. For information on factory recalibration, contact Data Translation at 508-946-5100 (if you are in the USA) of call your local distributor (if you are located outside the USA);...
Page 106: Technical Support
Chapter 7 Technical Support Note: TEMPpoint, VOLTpoint, and MEASURpoint instruments have a 1 year warranty from the factory. If you open the instrument’s enclosure, you will void this warranty. If you have difficulty using your TEMPpoint, VOLTpoint, or MEASURpoint instrument, Data Translation’s Technical Support Department is available to provide technical assistance.
Page 107: If Your Instrument Needs Factory Service
Troubleshooting If Your Instrument Needs Factory Service Most hardware models can be functionally tested, evaluated for repairs (if needed), and calibrated to factory specifications. An RMA # must be obtained from Application Engineering in advance of sending any product back to Measurement Computing. Customers outside of the USA must contact their local distributor for a return procedure.
Page 108 Chapter 7...
Page 109: Appendix A: Specifications
Specifications Basic Instrument Specifications ..........Thermocouple Specifications .
Page 110: Basic Instrument Specifications
Appendix A Basic Instrument Specifications Table 7 lists the basic instrument specifications for the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. For basic environmental specifications, please see page 124. Table 7: Basic Instrument Specifications Feature Specifications Number of channels in channel list...
Page 111: Thermocouple Specifications
+10 nA DT9871: +100 nA System temperature error DT9871U and DT9874: Table 9 Table 10 on page 112 DT9871: Table 11 on page 114 a. Older versions of the DT9871 instrument may support a maximum sampling rate of 7.5 Samples/s.
Page 112: System Temperature Error For The Dt9871U And Dt9874
Appendix A System Temperature Error for the DT9871U and DT9874 Table 9 lists the typical accuracy of the DT9871U and DT9874 for each thermocouple type at several temperature points over the dynamic range of the instrument. Table 9: Typical Thermocouple Accuracy of the DT9871U and DT9874 Thermocouple Type Input Temp.
Page 113 Specifications The histograms shown in Figure 36 Figure 37 characterize the Gaussian system noise distribution for each of the available filter types on the DT9871U and DT9874. Note that converting V error to temperature error depends on thermocouple type. For example, a K thermocouple changes approximately 39 V per degrees C;...
Page 114: System Temperature Error For The Dt9871
Figure 38 Figure 39 characterize the Gaussian system noise distribution for each of the available filter types on the DT9871. Note that converting V error to temperature error depends on thermocouple type. For example, a K thermocouple changes  approximately 39 V per degrees C; therefore, a noise level of 10 V adds 0.3 C error (10 V / 39 V) for a type K thermocouple.
Page 115 Specifications Figure 38: System Noise on the DT9871 Using No Software Filter (Raw Filter) Figure 39: System Noise on the DT9871 Using the Moving Average Filter...
Page 116: Rtd Specifications
Appendix A RTD Specifications Table 12 lists the specifications for RTD channels on the DT9872 and DT9874. Table 12: RTD Specifications Feature Specifications    RTD types (software-selectable) Platinum 100 , 500 , and 1000 A/D converter resolution 24-bits Sample rate 10 Samples/s Supported temperature range...
Page 117: Temperature Specifications
Specifications Temperature Specifications Table 14 lists the temperature specifications for thermocouple channels on the DT9871, DT9871U, and DT9874 instruments. Table 14: Temperature Specifications for Thermocouple Channels Feature Specifications Additional error due to ambient temperature change J-type thermocouple: 0.010C per degree ambient change, typical K-type thermocouple: 0.011C per degree ambient change, typical...
Page 118 Appendix A Table 15 lists the temperature specifications for RTD channels on the DT9872 and DT9874. Table 15: Temperature Specifications for RTD Channels Feature Specifications System temperature error Pt100: Offset (typical): ±0.03° C Offset (maximum): ±0.30° C RMS noise: 0.03° C Temperature resolution: 0.002°...
Page 119: Voltage Measurement Specifications
Specifications Voltage Measurement Specifications Table 16 lists the voltage measurement specifications for the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 16: Voltage Measurement Specifications Feature Specifications Input voltage range (no compensation) DT9871U and DT9874 thermocouple channels: ±0.0750 V DT9871: ±1.2500 V...
Page 120 Table 16: Voltage Measurement Specifications (cont.) Feature Specifications System drift error, zero  DT9871U and DT9874 thermocouple channels: ±0.02 V/C typical  DT9871: ±0.02 V/C typical  DT9872 and DT9874 RTD channels: ±0.10 V/C  DT9873 and DT9874 voltage channels: ±0.5...
Page 121: Isolation And Protection Specifications
Specifications Isolation and Protection Specifications Table 17 lists the isolation and protection specifications for the analog input subsystem on the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 17: Isolation and Protection Specifications Feature Specifications DT9871U, DT9871, and DT9874 Thermocouple Channels Overvoltage...
Page 122: Memory Specifications
Appendix A Memory Specifications Table 18 lists the memory specifications for the analog input subsystem on the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 18: Memory Specifications Feature Specifications Data memory onboard 4 MByte For Data logger built in, maximum time...
Page 123: Digital I/O Specifications
Specifications Digital I/O Specifications Table 19 lists the specifications for the digital input (DIN) and digital output (DOUT) subsystems on the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 19: Digital I/O Specifications Feature Specifications Number of digital I/O lines...
Page 124: Power, Physical, And Environmental Specifications
Appendix A Power, Physical, and Environmental Specifications Table 20 lists the power, physical, and environmental specifications for the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 20: Power, Physical, and Environmental Specifications Feature Specifications USB power   +5 V Standby:...
Page 125: Regulatory Specifications
Specifications Regulatory Specifications The DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments are CE-compliant. Table 21 lists the regulatory specifications for the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 21: Regulatory Specifications Feature Specifications Emissions (EMI) FCC Part 15, Class A...
Page 126: Connector Specifications
This section lists the specifications for the following connector types: • Thermocouple connectors • RTD connectors • Voltage connectors Thermocouple Connectors Table 22 lists the specifications for the thermocouple connectors used on the DT9871, DT9871U, and DT9874 instruments. Table 22: Thermocouple Connector Specifications Feature Specifications Thermocouple jacks Omega plugs SMPW-U-M –...
Page 127: Rtd Connectors
Phoenix Contact 1803293 4-Position screw terminal block plug Phoenix Contact 1803594 Voltage Connectors Table 24 lists the specifications for the voltage connectors used on the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 24: Voltage Connector Specifications Feature Specifications 4-Position screw terminal block header...
Page 128: Specifications
Appendix A External Power Supply Specifications Table 25 lists the specifications for the EP361 +5 V external power supply that is used with the DT9871, DT9871U, DT9872, DT9873, and DT9874 instruments. Table 25: External Power Supply (EP361) Specifications Feature Specifications...
Page 129 Connector Pin Assignments...
Page 130 Appendix B Table 26 lists the pin assignments for the 37-pin digital I/O connector on TEMPpoint, VOLTpoint, and MEASURpoint instruments. Table 26: Digital I/O Connector Pin Assignments Description Description Digital Input 0+ – Digital Input 1+ Digital Input 0– Digital Input 2+ Digital Input 1–...
Page 131 Index Index voltage inputs to RTD channels voltage inputs to thermocouple channels accessories voltage inputs to voltage channels accuracy specifications, thermocouple applying power administrator privileges attaching the instrument to the computer alpha curves analog input basic instrument specifications calibration block diagrams channels DT8871 CJC circuit...
Page 132 Index data encoding input ranges data format installing the software RTD channels isolation thermocouple channels isolation specifications voltage channels IVI-COM driver device driver Device Selection window differential channels LEDs digital I/O channel-to-channel functional isolation connecting input signals Power connecting output signals lines legacy CPL elevated operation modes...
Page 133 Index temperature thermocouple QuickDAQ thermocouple connectors Advanced FFT Analysis option voltage connectors Base version voltage measurement FFT Analysis option STP37 screw terminal panel system requirements system temperature error rack mounting raw filter recommendations for wiring technical support regulatory specifications temperature error requirements temperature specifications resolution...
Page 134 Index voltage inputs to RTD channels voltage inputs to thermocouple channels voltage inputs to voltage channels warm-up time...

This manual is also suitable for:

Dt9871u Dt9872 Dt9873 Dt9874

Data Translation DT9871 User Manual

About this Manual

Chapter 1: Overview

Part 1: Getting Started

Chapter 2 : Preparing to Use the

Instrument

Chapter 3: Setting up and Installing

The Instrument

Chapter 4: Wiring Signals

Chapter 5 : Verifying the Operation

Of Your Instrument

Part 2: Using Your Instrument

Chapter 6: Principles of Operation

Chapter 7: Troubleshooting

Appendix A: Specifications

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Summary of Contents for Data Translation DT9871

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Table of Contents