NI-SCOPE Output on PFI0 or PCI1 for 5122

[Steve_G]

Hello,

I am somewhat new to NI-Scope.  I have a 5122 card and would like to output a single TTL pulse on either PFI0 or PFI1.  I don't want it to be triggered or anything.  Basically, on my front panel I'll have a button that says "Pulse" and when I press it the appropriate PFI will output the single pulse.  I've tried using NIScope Export Signal.vi but can't seem to get it to work.

Thanks for any assistance!

Steve

[griffindore]

Hi Steve,

One thing you can try to do is to export the 5 V Power (13) using the niScope Export Signal VI when the button is pressed and then immediately call the VI again to export None (0).  Let me know if this works for you.

[Steve_G]

Mike,

Thanks for the reply.

I've tried using the 5 volt power (13) but when I do I get eror -1074135022, which says that the attribut or property is not supported.  Actually, I get this error from the Initiate Acquisition vi, which I realize I really shouldn't be using since I'm not doing an acquisition.  When I put that vi in a case statement so that its not used, I don't get any errors, but the line doesn't go high.

I've attached my vi so that you can look at it.  I've tried it configuring the horizontal and vertical properties, which is why they are in a case statement as well.

 I hope this makes sense....  Thanks

Steve

[griffindore]

Hi Steve,

I ran into the same problem. This was reported to R&D (# 126473) for further investigation. Do you have a requirement to only output a single pulse? If it's ok to send multiple pulses when you wish to send the trigger, you can use the "niScope Probe Compensation Signal Start.vi"and "niScope Probe Compensation Signal Stop.vi" to export a 1 kHz square wave output on PFI 1. Let me know if that works for you at all.

[Steve_G]

Mike,

Thanks for letting me know about the single pulse problem.  Unfortunately, a pulse train won't work for my application.  Let me explain a little more what I need to do.

I have a 5122 card and I would like to acquire data continuously.  There will be a button on my front panel that will say Acquire Data and when I press it the card will start taking data.  My data generation will need to begin with the acquisition, which is why I need the pulse.  The data generation board is configured to begin its sequence of data generation whenever it receives a trigger signal, so if I use the Probe Compensation vi's at 1kHz then my data will keep starting over until I call the Stop vi.  So, this pulse that I need will do two things - trigger my data generation and also trigger my data acquisition.  The data acquisition will stop when I press a Stop Acquisition button.

I had previously posted in the discussion forums about performing a continuous triggered acquisition with the 5122 card:  http://forums.ni.com/ni/board/message?board.id=150&message.id=2034#M2034.  As you see in the link (3784.vi) I can use this vi with a trigger pulse on PFI1 or PFI0 to start my continuous acquisition.  I was hoping to use this same trigger pulse to begin my data generation so that they would be timed together.

I'm not sure about this but it look like the Probe Compensation vi may also stop the acquisition.  Will the first pulse arm (start) the acquisition, and then the second pulse will be interpretted as the reference (stop) trigger?  Again, I'm still learning about NI-Scope.

Thanks for any guidance you can give me!

Steve

[griffindore · Accepted solution]

Hi Steve,

I want to make sure that I understand you correctly. You're wanting to output a signal on one of the PFI lines when you're scope begins its acquisition. If that's correct, you can use the Export Signal VI and choose to export the Start Trigger. This should output a pulse when the acquisition begins. Let me know if that works for you.