AppendixC CommonQuestions
ATE Series User Manual C-4 ni.com
I’m usingthe DACsto generate a waveform, but I discoveredwith a
digital oscilloscope that therea reglitches on the o utput signal. Is this
normal?
Whenit switches from on evoltage to another, any DAC produces glitches
due to released charges.The largest glitches occur when the most
significantbit (MSB) of the D/A code switches. You can build a lowpass
deglitchingfilter to remove some of these glitches, depending on the
frequencyand nature of t heo utput signal. The AT-MIO-16E-1,
AT-MIO-16E-2and the AT-MIO-64E-3 devices have built-inreglitchers,
which canbe enabled through software, on their AO channels. Refer to
the Analog Output Reglitch Selection section of Chapter 3, Hardware
Overview,f or more information about reglitching.
Can I synchronizea one-channel AI data acquisition with a
one-channelAO waveform generation on my AT E Series device?
Yes.One way to accomplish this synchronization is to use the waveform
generation timing pulses to control the AI data acquisition. Todo this,
followsteps 1 thro ugh 4, in addition to the usual steps for data acquisition
and waveformgeneration 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 Route Signal VI with signal name
set to PFI5an d signal source set to AOUpdate.
2. Setup DAQ 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).
Ify ou are using LabVIEW,invoke AI Clock Config VI with clock
sourcecode set to PFI pin, high to low, and clock source string set to 5.
3. InitiateA I data acquisition, which starts only when the AOwaveform
generation starts.
Forexample, if you are using NI-DAQ, you can call DAQ_Start with
appropriate parameters.
Similarly,if you are using LabVIEW, you can invoke AI Control VI
with controlc odeset to 0 (start).