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NI 6703/6704 Calibration
Procedure for Traditional NI-DAQ
Introduction
Note
Refer to
ni6704Cal.dll
Calibration Options: External Versus Internal
This document contains instructions for calibrating the NI 6703/6704 for
PCI/PXI/CompactPCI using Traditional NI-DAQ. Use this calibration
procedure with the
ni6704Cal.dll
required for calibrating the NI 6703/6704.
The NI 6703/6704 should be calibrated at a regular interval as defined by
the measurement accuracy requirements of your application. National
Instruments recommends that you perform a complete calibration at least
once every year. You can shorten this interval to 90 days or six months.
ni.com/support/calibrat/mancal.htm
file.
NI 6703/6704 products have two calibration options, an internal or
self-calibration, and an external calibration.
Internal Calibration
The NI 6703/6704 is continuously applying corrections to the output levels
based on previous calibration results. Both the NI 6703 and the NI 6704
have 16 voltage outputs and two voltage calibration channels. The NI 6704
also has 16 current outputs and two current calibration channels. All the
output and calibration channels are scanned and refreshed together. The
outputs of the calibration channels for the NI 6703/6704 are continuously
compared to the onboard reference, and the offset and gain of the 16-bit
digital-to-analog converter (DAC) are adjusted to minimize the error of the
calibration channels. Because the NI 6703 and NI 6704 have excellent
channel-to-channel matching of offset and gain errors, minimizing the error
on the calibration channels also minimizes the error for all of the voltage
and current outputs.
file, which contains specific functions
for a copy of the

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Summary of Contents for National Instruments NI 6703

  • Page 1 NI 6703/6704. The NI 6703/6704 should be calibrated at a regular interval as defined by the measurement accuracy requirements of your application. National Instruments recommends that you perform a complete calibration at least once every year.
  • Page 2: External Calibration

    External Calibration External calibration requires a high-precision digital multimeter (DMM) to measure error on the NI 6703/6704 outputs. The error is then corrected with a set of calibration constants that adjust the offset and gain of the 16-bit DAC to ensure that the output voltages and currents are within the device specifications.
  • Page 3 Install the NI 6703/6704 in an available slot. Power on the computer. Launch Measurement & Automation Explorer (MAX). Configure the NI 6703/6704 device number. Click the Test Resources button to ensure that the NI 6703/6704 is working properly. The NI 6703/6704 is now configured. Note After a device is configured in MAX, the device is assigned a device number.
  • Page 4 PCI/PXI-6703/6704 User Manual. Calibrating the NI 6703/6704 To calibrate the NI 6703/6704, complete the following steps: Verify the performance of the NI 6703/6704. This step, which is covered in the Verifying the Performance of the NI 6703/6704 section, confirms whether the device is in specification prior to adjustment.
  • Page 5 Call the function contained in Get_Cal_Date ni6704Cal.dll determine the previous calibration date of the NI 6703/6704. Connect the DMM to the NI 6703/6704 as shown in the following table. Signal Name Description NI 6703/6704 Output DMM Input VCH0...
  • Page 6 NI 6703/6704 passes voltage verification. 10. Disconnect the DMM from the NI 6703/6704. You have now verified the voltage output of the NI 6703/6704. Verifying Current Output (NI 6704 Only) This procedure verifies that the current output of channel 16 is within specifications.
  • Page 7 Adjusting the NI 6703/6704 At the end of each calibration procedure, new constants are stored in the user calibration area of the NI 6703/6704, ensuring that the device stores a permanent record of the calibration constants. Storing the calibration constants here also ensures that the constants automatically load when the NI 6703/6704 is powered on.
  • Page 8 Set the following parameters: • infoType: ND_CALIBRATION_ENABLE • infoValue: ND_YES Connect the DMM to the NI 6703/6704 as shown in the following table. Signal Name Description NI 6703/6704 Output DMM Input VCH0 Voltage Channel 0...
  • Page 9 16. Call to generate 20.0 mA on current channel 16. Set the AO_VWrite following parameters: • chan: 16 • voltage: 20.0 © National Instruments Corporation NI 6703/6704 Calibration Procedure for Traditional NI-DAQ...
  • Page 10: Saving Calibration Values

    NI 6703/6704 EEPROM to ensure that the new calibration values are permanently saved and automatically loaded when the NI 6703/6704 is powered on. If the calibration is being performed by a metrology laboratory or another facility that maintains traceable standards, the calibration values should also be stored in the factory calibration area.
  • Page 11: Specifications

    The 1-Year Ranges column contains the upper limits and lower limits for the test point value. If the NI 6703/6704 has been calibrated in the last year, the test point value should be between the upper and lower limit values.
  • Page 12 19.995565 20.004435 Flowcharts The following flowcharts show the appropriate NI-DAQ function calls for verifying and adjusting the NI 6703/6704. Refer to the Calibrating the NI 6703/6704 section of this document, the Traditional NI-DAQ Function Reference Help, and the NI-DAQ User Manual for PC Compatibles for additional information about the software structure.
  • Page 13 Connect the DMM to current channel 16. AO_VWrite(deviceNumber,16,voltage) Verify that the current read by the DMM is within range. Figure 2. Current Output Verification (NI 6704 Only) © National Instruments Corporation NI 6703/6704 Calibration Procedure for Traditional NI-DAQ...
  • Page 14 Adjust voltage until the DMM reads 0.0 V. AO_VWrite(deviceNumber,0,10.0) NI 6703: AO_VWrite(deviceNumber,17,voltage) Adjust voltage until the DMM reads 10.0 V. NI 6704: AO_VWrite(deviceNumber,34,voltage) Adjust voltage until the DMM reads 10.0 V. Figure 3. Voltage Output Adjustment NI 6703/6704 Calibration Procedure for Traditional NI-DAQ ni.com...
  • Page 15 Connect the multimeter to current channel 16. AO_VWrite(deviceNumber,16,0.1) AO_VWrite(deviceNumber,33,voltage) Adjust voltage until the DMM reads 0.1 mA. AO_VWrite(deviceNumber,16,20.0) AO_VWrite(deviceNumber,35,voltage) Adjust voltage until the DMM reads 20.0 mA. Figure 4. Current Output Adjustment (NI 6704 Only) © National Instruments Corporation NI 6703/6704 Calibration Procedure for Traditional NI-DAQ...
  • Page 16 National Instruments Corporation. Product and company names mentioned herein are trademarks or trade names of their respective companies. For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your CD, or...

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