Sample Clock and Digital Waveform (1Channel NSamples)

[SergeS]

I need to sampling digital input using NI USB-6001 device. I have never do sample digital inputs before, but did it many times for analog inputs, so I just copy sampling part from another project with analog inputs and make some adjustments, see screenshot below. Now I have a problem with Sample Clock, it gives me error -200077. Bypassing Sample Clock is working, but it is not what I need, I need to specify rate. Where is my mistake and how to do it properly?

[Kevin_Price · Accepted solution]

The problem is that your device simply does not support the use of a sample clock for Digital tasks.  That's the meaning of the help text stating that only "On Demand" sampling is valid.  This is sometimes called "software-timed" acquisition. Your application software queries for a sample when it chooses to, and one is delivered on-demand at that moment.  But the device can't free run in the background with a sample clock and buffer.

-Kevin P

[SergeS]

Ok, thank you. Have done it by reading digital input in the loop. I do not need precise timing so it is ok for me.