National Instruments DAQ PCI E Series User Manual page 129

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I'm using the DACs to generate a waveform, but I discovered with
a digital oscilloscope that there are glitches on the output signal. Is
this normal?
When it switches from one voltage to another, any DAC produces
glitches due to released charges. The largest glitches occur when the
most significant bit (MSB) of the D/A code switches. You can build a
lowpass deglitching filter to remove some of these glitches, depending
on the frequency and nature of your output signal. The PCI-MIO-16E-1
and PCI-6071E boards have built-in reglitchers, which can be
software-enabled, on its analog output channels. See the Analog Output
Reglitch Selection section in Chapter 3, Hardware Overview, for more
information about reglitching.
Can I synchronize a one-channel analog input data acquisition with
a one-channel analog output waveform generation on my
PCI E Series board?
Yes. One way to accomplish this is to use the waveform generation
timing pulses to control the analog input data acquisition. To do this,
follow steps 1 through 4 below, 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 Route Signal VI with signal
name set to PFI5 and signal source set to AO Update.
2. Set up data 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 AI Clock Config VI with
clock source code set to PFI pin, high to low, and clock source
string set to 5.
3. Initiate analog input data acquisition, which will start only when
the analog output waveform generation starts.
4. Initiate analog output waveform generation.
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C-3
Appendix C Common Questions
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PCI E Series User Manual