counter output for 9401

[wp_tu]

Hi everyone!

I?m using CompactDAQ with ni9401 digital I/O module and I would like to generate two parallel pulse output signals. For a start-up I tried it with the ?Gen Dig Pulse Train Finite.vi? from the example database which works fine for one channel (couter) only. But as soon I select both counters I get the message that the specified resource is reserved and the operation could not be completed. As I found out in an older topic it seems the ctr1 is needed to tell ctr0 when the finite pulse signal is finished. My question now is it somehow possible to use both counters at the same time to write pulses on two digital outputs. Or is the at least some other way in which I can, with my hardware, write two parallel pulse signals where each one has a specific number of pulses?  

 

wolfgang

 

[Wolfgang Z.]

Hello Wolfgang,

For the a Finite Pulse Generation you need two counters. The first counter produce the pulses, the second counter count the pulses.

Note: If you program a Continous Pulse Generation you need only one counter!

You can test this If you duplicate the example "Gen Dig Pulse
Train-Continous.vi" from Example Finder. Put the NI 9401 in Slot 6. I
have measured the two Signals from Counter Output 0 and 1 on pin 19 and
25 (default settings).

Best Regards,
Wolfgang Z

[wp_tu]

Thx for the
explanation!


I did in
the mean time what both of you are suggesting and realized my application with
the continuous pulse generation using an external stop criterion.


The counter
output pins were a little handicap as well since there seemed to be no
documentation on where to find them. But as Wolfgang Z mentioned they are to be
found as number 19 and 25.


Thx again


 


Wolfgang P

[Wolfgang Z.]

Hello Wolfgang,

The easiest way to get the pinout of a DAQ device is to go to MAX.
There look at NI-DAQ Devices => NI cDAQ-9172 => NI 9401.
Right mouse click to NI 9401 and choose pinout.
You get the pinout of the Connector and the Default NI-DAQmx Counter Terminals.

Regards,
Wolfgang Z