National Instruments SCXI-1141, Calibration Procedure

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SCXI-1141/1142/1143 Calibration Procedure 8 ni.com
Verifying Filter Parameters
Complete the following steps to set up the SCXI-1141/1142/1143 for this
verification process:
1. Read the Test Conditions section in this document.
2. Ensure that the E Series DAQ device is connected to the
SCXI-1141/1142/1143.
3. Call
SCXI_Configure_Filter
to enable the cutoff filter.
Set the following parameters:
• SCXIchassisID —The value obtained from MAX
• moduleSlot —1
• channel —0
• filterMode —1
• freq —10 kHz
• cutoffDivDown —0
• outClkDivDown —2
4. Call
SCXI_Set_Gain
to configure the module to a gain of 1.
Set the following parameters:
• SCXIchassisID —The value obtained from MAX
• moduleSlot —1
• moduleChan —0
• gain —1
5. Connect the calibrator to analog input channel 0. Refer to Table 7 to
determine which pins on the 96-pin front connector correspond to the
positive and negative inputs of the specified channel. If you are using
an SCXI-1304 connected to the SCXI-1141/1142/1143, connect the
calibrator to the AI 0 + and AI 0 – inputs.
6. Connect the DMM to the output of channel 0. Refer to Table 8 to
determine which pins on the 50-pin rear connector correspond to the
positive and negative outputs for the specified channel. For example,
the positive output for channel 0 is pin 3, which is AI 0 +. The negative
output for channel 0 is pin 4, which is AI 0 –.
Verifying Stopband Attenuation
Verify the stopband attenuation by performing the following steps:
1. Set the calibrator to output a 10 kHz, 1 V
rms
sine wave.
2. With a DMM, ensure that you read a 1 V
rms
signal.
3. Increase the input signal frequency generated by the calibrator until the
level read by the DMM is 10 mV
rms
.