Appendix C
Common Questions
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National Instruments Corporation
C-5
Can I synchronize a one-channel AI data acquisition with
a one-channel AO waveform generation on the device?
Yes. Use the waveform-generation timing pulses to control the AI data
acquisition. To do this, follow steps 1 through 4, in addition to the usual
steps for data acquisition and waveform generation configuration.
1.
Enable the PFI5 line for output, as follows:
•
If you are using NI-DAQ, call
Select_Signal(deviceNumber, ND_PFI_5,
ND_OUT_UPDATE, ND_HIGH_TO_LOW)
.
•
If you are using LabVIEW, invoke the Route Signal VI with signal
name set to PFI5 and signal source set to AO Update.
2.
Set up the acquisition timing so that the timing signal for A/D
conversion comes from PFI5, as follows:
•
If you are using NI-DAQ, call
Select_Signal(deviceNumber, ND_IN_CONVERT,
ND_PFI_5, ND_HIGH_TO_LOW)
.
•
If you are using LabVIEW, invoke the AI Clock Config VI with
clock source code set to PFI pin, high to low, and clock source
string set to 5.
3.
Initiate AI data acquisition, which starts when the AO waveform
generation starts.
4.
Initiate AO waveform generation.
Can I programmatically enable channels on the NI 6052E to acquire in
different modes? For example, can I configure ACH 0 in DIFF input
mode and ACH1 in RSE input mode?
You can enable channels on the NI 6052E to acquire in different modes, but
different pairs of channels are used in different modes. In the example
configuration given above, ACH0 and ACH8 are configured in DIFF mode
and ACH1 and AIGND are configured in RSE mode. In this configuration,
ACH8 is not used in a single-ended configuration. To enable multiple mode
scanning in LabVIEW, use the coupling and input configuration cluster
input of the AI Config VI. This input has a one-to-one correspondence with
the channel array input of the AI Config VI. You must list all channels
either individually or in groups of channels with the same input
configuration. For example, if you want ACH0 to be in DIFF mode, and
ACH1 and ACH2 to be in RSE mode, Figure C-1 demonstrates how to
program this configuration in LabVIEW.
