©
National Instruments Corporation
19
NI 446X Calibration Procedure
12. Repeat steps 2 through 11 for all remaining gain values used in step 5.
Modify the calibrator output amplitude in step 2. Refer to Table 3 for
the calibrator output amplitude and the device gain value.
13. Repeat steps 1 through 12 for all remaining analog input channels of
the device. Replace
ai0
with the appropriate channel name in function
call parameters
physicalChannel
and
channel
.
Verifying Analog Output Performance
This section verifies the analog output (AO) performance on the NI 4461
devices. Refer to the
NI 446X Specifications
for the number of channels,
gain settings, and performance specifications.
Verifying AO DC Offset
Complete the following steps to verify AO DC offset:
1.
Connect the analog output channel 0 of the device to the input of the
multimeter.
2.
Create an array of double float of size 1024. Initialize all the values in
the array to 0.0. You use this array to output 0 V using the device
analog output channel 0.
3.
If you use C function calls, create a task using the following function.
If you use LabVIEW, skip this step. The task is created in step 4 in
LabVIEW.
Table 3.
AI Gain Accuracy Limits
Device Gain
Calibrator Output
Amplitude (VDC)
Device Input Amplitude Accuracy
Min (dB)
Max (dB)
Min (V)
Max (V)
–20
9.0
– 0.03
0.03
8.9690
9.0311
–10
9.0
– 0.03
0.03
8.9690
9.0311
0
9.0
– 0.03
0.03
8.9690
9.0311
10
3.0
– 0.03
0.03
2.9897
3.0104
20
0.9
– 0.03
0.03
0.8969
0.9031
30
0.3
– 0.03
0.03
0.2990
0.3010
NI-DAQmx Function Call
LabVIEW Block Diagram
Call
DAQmxCreateTask
with the following parameter:
taskHandle
:
mytaskHandleReturnValue
LabVIEW does not require this step.