multiple counters started simultanously

[LVilla]

I have a PCI 6071E board and a PCI 6602 board Can I start 1 counter, 6
single pulses with different delays, 3 pulse trains and a multichannel
acquisition from a single line that triggers them all?
Whant CVI staements are involvd?
I suppose I need a RTSI connector for this. Do Ijust plug it in or is there
any software configuration neded?

Thanks

L Villa

[markwysong]

The answer is yes, you can trigger them all. You will need the RTSI cable to connect your two boards. Since I have LabVIEW instead of CVI, I can't provide the exact statements that you'd need to set up the trigger lines, but I can tell you how it would be done in LabVIEW, and you'll at least know what to look for in CVI,

First, all the counter functions, specifically pulse trains and single pulses can be triggered by setting a parameter of the counter to "trigger on gate". While the gate of the counter is defaulted to a specific line, there is also a parameter to set where the counter looks for it's gate; set that to the RTSI line you want the control pulse (RTSI line 0-9).

Set all your counters to have the gate as the same RTSI line. (All the gates are input
s.) Then setup your multichannel acquisition for digital triggering. There is also a call to set the line that will be used for the trigger; this should be set to the same RTSI line.

Finally, you make the call to connect some output (maybe the output of another counter) to drive the RTSI line. If all counters and data acquisition have been started prior to this output toggling, they should be waiting for the trigger. When the toggle happens, all your outputs and acquisition will go together.

Mark

[Jeff.F]

I have a similar quandry.  I want to…

• run two counters as outputs on one device (PXI-6289 M Series aka “MFDAQ”) simultaneously at different frequencies
• /MFDAQ/ctr0 will be a finite pulse train at 2kHz
• /MFDAQ/ctr1 will be a pulse train at 10Hz (finite or continuous – whichever works)
• start /MFDAQ/ctr1 when ctr0 starts
• /MFDAQ/ctr1 needs to terminate upon completion of the /MFDAQ/ctr0 pulse train (or ctr1 can be a finite train itself if that’s possible)
• /MFDAQ/ctr0 will be routed to /MFDAQ/PXI_Trig0 to trigger…
• the PXIe-1435 frame grabber & camera via their RTSI0 line.
• another AI DAQmx task capturing inputs at the same rate as the camera.
• The AI DAQmx task will trigger from /MFDAQ/PXI_Trig0

The trigger pulse train, video & AI work fine.  I can’t seem to get two counters on the same device running at different frequencies to work.  I have moved to a simplified app that just attempts to put two counters on the same device with the same task or separate tasks.  I’m starting to gather that one device can have only one CO task running on it simultaneously.  Thoughts anyone?

-Jeff 

[Kevin_Price]

On a M-series device, a finite pulsetrain uses both counters.  The output pulses are generated on the counter you explicitly specify for the task, but the other counter is used behind the scenes to make a precision-timed gating signal which sorta-indirectly controls the # of pulses generated.

You *can* generate 2 counter outputs, but only if neither task is set for "Finite Sampling".   Dunno if your app can handle generating both pulse trains with "Continuous Sampling", using software-timing to choose when to stop them, and then do some more software post-processing to clean up the mess left over from the extra pulses.

As I mentioned on another thread recently, you *might* be able to use a dummy Finite Sampling AO task and export its clock as one of your counter channels.  Another avenue you might be able to consider is that the newer X-series boards can generate finite pulse trains without consuming a "helper" counter.  

-Kevin P