Sample rate for digital sampling (cDAQ-9172 & NI 9401)

[andreskareberg]

Hi!

I have a cDAQ-9172 with a NI 9401 C-series module (digital). I would like to sample the digital inputs with a sample rate of e.g. 400 kHz or 200 kHz. My problem is that I can only select a the 100kHzTimebase clock, and therefore only get a 100 kHz sample rate. The 20MHzTimebase clock is too fast, since it gives me a sample rate of 20 MHz). Is it possible to get a user defined sample rate of e.g. 200 kHz, by e.g. dividing down the 20MHzTimebase clock?

[RedAG]

Try this link http://digital.ni.com/public.nsf/allkb/33EFB527E17AFCB68625765E007521EC

It's not exactly your device but I think your series. 

[MarkGrot]

The cDAQ-9172 chassis does not have an internal timing engine for digital input however you can use one of the onboard counters to generate your clock.  Set your pulse train generation counter to be one of the internal counters, such as "cDAQ1/_ctr0" and your digital input sample clock source to be /cDAQ1/Ctr0InternalOutput". 

[andreskareberg · Accepted solution]

Thanks! Last post and this article Using Internal Counters on a NI cDAQ Chassis solved my problem.