Figure b-1. ai/sampleclock and ai/convertclock, Analog output – National Instruments DAQ M Series User Manual
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Appendix B
Troubleshooting
B-2
ni.com
reference the signal to the same ground level as the device reference. There
are various methods of achieving this reference while maintaining a high
common-mode rejection ratio (CMRR). These methods are outlined in the
Connecting Analog Current Input Signals
section of Chapter 4,
.
How can I use the AI Sample Clock and AI Convert Clock signals on
an M Series device to sample the AI channel(s)?
M Series devices use ai/SampleClock and ai/ConvertClock to perform
interval sampling. As Figure B-1 shows, ai/SampleClock controls the
sample period, which is determined by the following equation:
1/sample period = sample rate
Figure B-1. ai/SampleClock and ai/ConvertClock
ai/ConvertClock controls the convert period, which is determined by the
following equation:
1/convert period = convert rate
This method allows multiple channels to be sampled relatively quickly in
relationship to the overall sample rate, providing a nearly simultaneous
effect with a fixed delay between channels.
Analog Output
I am seeing glitches on the output signal. How can I minimize it?
When you use a DAC to generate a waveform, you may observe glitches on
the output signal. These glitches are normal; when a DAC switches from
one voltage to another, it produces glitches due to released charges. The
largest glitches occur when the most significant bit of the DAC code
Channel 0
Channel 1
Convert Period
Sample Period