National Instruments 446 Series Calibration Procedure page 15

NI-DAQmx Function Call
Call
DAQmxCreateTask
taskHandle:
mytaskHandleReturnValue
© National Instruments Corporation
10. Average all the values in the array returned from the acquisition. The
average is the resulting offset for AI 0 at –20 dB device gain setting.
Compare this value to the limits in Table 2.
Device Gain
–20
–10
0
10
20
30
11. Repeat steps 2 through 10 for each different gain value that is set in
step 4, using the device gain values in Table 2.
12. Repeat steps 1 through 11 for all remaining analog input channels of
the device. Replace
call parameters
physicalChannel
Verifying AI Gain Accuracy
Complete the following steps to verify AI gain accuracy:
1. Connect the output of the calibrator to the analog input channel 0 of the
device.
2. Output 9.0 VDC using the calibrator.
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.
with the following parameter:
You use the object
function calls.
Table 2. AI Offset Limits
Device Input Offset
Min (mV)
–7.0
–5.0
– 0.7
– 0.5
– 0.2
– 0.1
with the appropriate channel name in function
ai0
and
LabVIEW Block Diagram
LabVIEW does not require this step.
in all subsequent NI-DAQmx
myTaskHandle
15
Max (mV)
7.0
5.0
0.7
0.5
0.2
0.1
.
channel
NI 446X Calibration Procedure