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National Instruments Corporation
15
SCXI-1141/1142/1143 Calibration Procedure
•
filterMode
—0
•
freq
—0 kHz
•
cutoffDivDown
—0
•
outClkDivDown
—0
9.
Connect the calibrator to analog input channel 0. Refer to Table 7
to determine the pins on the 96-pin front connector that 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.
10. Connect the DMM to the output of channel 0. Refer to Table 8 to
determine the pins on the 50-pin rear connector that 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
input for channel 0 is pin 4, which is AI 0 –.
11. Set the calibrator voltage to 3.4 V
rms
, 400 Hz.
12. Measure and record the amplitude of the sine wave with the DMM.
13. Call
SCXI_Configure_Filter
to disable the filter bypass. Set the
following parameters:
•
SCXIchassisID
—The value configured in MAX
•
moduleSlot
—4
•
channel
—0
•
filterMode
—1
•
freq
—25 kHz
•
cutoffDivDown
—0
•
outClkDivDown
—2
14. Measure the amplitude of the sine wave at the output and adjust the
potentiometer until the amplitude is at the same level as it was with the
filter in bypass mode.
15. Repeat steps 8 through 14 for the remaining channels.
You have finished adjusting the filter AC gain of the
SCXI-1141/1142/1143.
SCXI-1141/1142/1143 Revision F or Later
Complete the following steps to adjust the AC gain of the filter on an
SCXI-1141/1142/1143 revision F or later:
1.
Read the
section in this document.
2.
Ensure that the E Series DAQ device is connected to the
SCXI-1141/1142/1143.
