SCXI-1125Calibration Procedure 6 ni.com
13. Call SCXI_Scale.Set the followingparameters:
•SCXIChassisID—The value assigned by MAX
•moduleSlot—1
•channel—The samech annel number from step 7
•SCXIgain—The same gain value from step 9
•TBgain—1
•DAQboard—The devicenumber for th e DAQdevice
•DAQChannel—0
•DAQgain—1 for 16-bit devices, –1 for 12-bit devices
•numPoints—5.000
•binArray—The array returned from the DAQ_Op function
The resulti sa setof scaled voltages that you read from the SCXI
module.
14. Averagethe results returned from the SCXI_Scale function. Compare
theaveraged result to the upper and lower limits in Table 1. If the result
fallswith in these limits, your module has passed this portion of the
test.If it does not, your module needsto be adjusted using the steps in
the nexts ection, Adjusting for Gain and Offset Errors.
15. Repeatsteps 8through 14 for the remaining gains.
16. Repeatsteps 7through 15 for the remaining channels.
Youhave now finished verifying your SCXI-1125.
Note If all channels fall within the upper and lower limits, your device does not need to
be adjusted.
Adjusting for Gain and Offset Errors
The following two sections explain how to determine the gain and offset
errorsof y ourSCXI-1 125 and how to adjust the calibration constants to
correctfor these errors.
Determining Gain and Offset Errors
Completethe following steps to determine the gain and offset errors of the
SCXI-1125:
1. Read the Test Conditions section.
2. Connect the E Series deviceto the SCXI-1125.
3. Call Calibrate_E_Seriesto minimize the uncertainty associated
with the Eseries device measurements. Set the following parameters:
•deviceNumber—The valueassigned by MAX