Buffered Digital Output on NI9401

[Laser]

Hello All,

I have a cDAQ system with different modules inside and  I used the system in the past without problem.

Now I'm having a new need: produce 8 different pulse train using the 8 lines of the module NI9401.

I succeed doing that, if I use single Write commands divided by Delay() function. Of course this is not the optimal solution.

I've tried using the buffered output but, for sure, I have not understood the mechanism.

Here attached the code I'm using for the preliminar test.

In the first image I get the error of slot position (I was currently using the system with NI9401 in slot 5).

In the second image I move the module to slot 3 and I get another error.

Is there anybody who can help me?

Thanks

Sergio

[Filippo_Persia]

Hi Laser,

It looks like a correlated Digital I/O to me.

You should check these two documents

NI-DAQmx: Correlated Digital I/O with NI CompactDAQ and LabVIEW

http://zone.ni.com/devzone/cda/epd/p/id/5256

Can I Use Different Sample Clocks for Correlated DI and DO?

http://digital.ni.com/public.nsf/allkb/79608CDF0C0D28AA862573400042D4F8?OpenDocument

Basically the 9401 isn't able to create a clock on it's own. You have to generate this clock "externally" I mean with another module.

You can chose either an analog input/output module and use the analog timebase (ai/sampleclock) to drive the digital I/O operation or use a digital module in slot 5 or 6 and use the counter to produce the clock needed (ctr0/internaloutput).

Hope this helps