PCI-6602, DAQmx, generate 7 synchronized finite pulse trains all gated by one counter

[microbreaker]

Hello,

on the PCI-6602, is it possible to generate 7 different (delayed with respect to eachother, and with different frequencies) finite pulse trains all internally gated by one counter ?

I'm thinking of using continuous pulse train generation for 7 counters, and then generating a single pulse with the 8th counter. Can this 8th counter programmatically gate the 7 other counters, or does it have to be hard wired ?

Also, so far, I've been simply generating 6 continuous pulse trains, all starting by the same start trigger pulse, and simultaneously generating 1 finite pulse train, also starting with the same start trigger pulse as the 6 continuous pulse trains and then I add a DAQmxIsTaskDone at the end of the finite pulse train, and when this is true, this ends the 6 continuous pulse trains, but there seems to be a little time lag between the end of the finite pulse train and the end of the continuous pulse trains, since my continuous pulse train always end up generating one more pulse than the finite one.

Is there a way to (without hard wiring) use the gating signal from the finite pulse train to gate all continuous pulse trains ?

thanks !

Marc

[Benjamin38]

Hi Marc,

I apologize for not seeing your post earlier when you posted this question, we have been dealing with a bit of a web issue of late.  To address your question (if you haven't answered it for yourself at this point) : 

In DAQmx programming you will not be able to utilize the same counter to generate more than one pulse train.  If you want to use the 8th counter to gate the other 7 internally this can be easily accomplished.  You can have a look at the KnowledgeBase here that will show you how to configure this pragmatically http://digital.ni.com/public.nsf/allkb/8A85E97855EDADC98625730C00065F58?OpenDocument.

Again, I apologize for the late reply.  Please feel free to let me know if you have already accomplished this task or if you have any further questions on it.  

[microbreaker]

Ben,

thank you much for your reply. I am now generating 7 continuous pulse trains, all started and paused (using a Trigger Property Node) by 1 long finite gating pulse. The long gating pulse is set in the program to be generated on counter ctr0, and on my bnc-2121 breakout box, the out0 is also PFI 36. So as a Pause trigger source for the 7 pulse trains, I simply had to choose PFI 36. So I didn't have to hard-wire anything. See attached VI.

Also, about the Trigger Property Node, the Pausing long gating pulse, when not on the pausing level (here i have it pause when low), seems to always start the pulse train at the beginning of a high, but when the long gating pulse goes back to low, it will stop the pulse train in whatever level it is when the long gating pulse went back to low . I am wondering if it would be possible for the pulse train to be forced to low when the long gating pulse goes to low.

Also, so far, I've been physically wiring my generated pulse trains to an analog in on my BNC-2090A, and sampling the signals at 100 kHz. Would it be possible to save those generated pulse trains in the program instead ? I feel like I shouldn't have to sample with labview signals that i am generating with labview.

What do you think of my VI ?

thanks a lot for your help !

Marc