Chapter 2
Using the SCXI-1530/1531
©
National Instruments Corporation
2-13
SCXI-1530/1531 for proper operation. You can use any of the DAQ device
analog input functions to get the data from the four or eight channels of the
SCXI module. After scanning, convert the binary data to voltage data by
using
SCXI_Scale
. See the NI-DAQ User Manual for additional
information on parallel scanning of SCXI modules.
Calibration
The SCXI-1530/1531 is shipped with a calibration certificate and is
calibrated by the factory to the specifications described in Appendix A,
. Calibration constants are stored inside the calibration
EEPROM and provide correction factors that are used by your application
development software. These values correct your measurements for both
offset and gain errors in the module.
Calibration Procedures
You can calibrate the offset and gain on the SCXI-1530/1531 using
National Instruments software. When calibrating the SCXI-1530/1531,
make sure the DAQ device you are using was recently calibrated or you
will invalidate the calibration on the SCXI-1530/1531. To perform internal
calibrations see the
section. Contact National
Instruments to obtain procedures to perform external calibrations.
Note
Ensure that the calibration on the DAQ device you are using is up to date and
traceable. If you adjust the gain or offset values using an uncalibrated device, you
invalidate the calibration on the SCXI-1530/1531. Any subsequent measurements taken
with the module may be inaccurate.
Remember that the calibration you perform on the SCXI-1530/1531 is only
as accurate as the calibration device you are using. Refer to Appendix A,
, for accuracy specifications for the SCXI-1530/1531.
Internal Calibration
To perform gain and offset calibration on your module, follow this
procedure if you are using LabVIEW:
1.
Make sure the DAQ device you are using has a valid calibration and
meets the accuracy specifications for your application.
2.
In LabVIEW, use the SCXI Calibrate VI to calibrate your module.
a.
Enter the DAQ device and the SCXI channel string for the module
you want to calibrate.