National Instruments SCXI-1104, Manual

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SCXI-1104 Calibration Procedure 6 ni.com
• DAQChannel — 0
• DAQgain —0 for 16-bit devices, –1 for 12-bit devices
• numPoints —100
• binArray —The array returned from the
DAQ_Op
function
The result is a set of scaled voltages that you read from the SCXI
module.
12. Average the results returned from the
SCXI_Scale
function. Compare
the averaged result to the upper and lower limits in Table 1. If the result
falls within these limits, your module has passed this portion of the
test. If it does not, use the steps in the next section,
Adjusting Gain and
Offset Errors and Calibration Constants , to adjust your module.
13. Repeat steps 7 through 12 for the remaining channels.
You have now completed verifying the operation of your SCXI-1104.
Note If all channels fall within the upper and lower limits, your module does not need to
be adjusted.
Adjusting Gain and Offset Errors and Calibration Constants
This section contains step-by-step instructions on adjusting gain and offset
errors and calibration constants.
Adjusting Gain and Offset Errors
Complete the following steps to adjust gain and offset errors in your
SCXI-1104:
1. Read the Test Conditions section.
2. Connect the E Series device to the SCXI-1104.
3. Call
Calibrate_E_Series
to minimize the uncertainty associated
with the E series device. Set the following parameters:
• deviceNumber —The value obtained from Measurement &
Automation Explorer
• calOp —
ND_SELF_CALIBRATE
• setOfCalConstants —
ND_USER_EEPROM_AREA
• calRefVolts —0.0
4. Call
AI_Configure
to put the E Series device in bipolar mode. Set the
following parameters:
• deviceNumber —The value obtained from Measurement &
Automation Explorer
• chan —0