external trigger different data channel

[velho]

I am trying to program a PCI 6251 to collect data on one channel and use an external trigger for the start trigger on a second channel.  Thus far I have been unsuccessful in my endevours.  I have looked at many of the examples provided and tried to modify them also, but to no avail.  Does anyone have a sample which collects voltage signal on two separate channels where one is a start trigger and the other is the sample data?

[Justin_M]

Hi velho,

If I understand you correctly, you want to collect data on one analog channel (let's say channel 1), and have that data be triggered by a signal going into another analog channel (let's say channel 2).  With the 6251 you can use an analog trigger, which fires when the voltage on an analog channel reaches a certain threshold.  I've created a simple example that shows how to do this (see attached).

If you have a digital trigger, I suggest using one of the PFI lines as the trigger instead of an analog line.  In that case, you would set the trigger to 'digital edge' instead of 'analog edge', and select the PFI line.

I hope this helps!

Justin M

National Instruments

[velho]

Justin,

I appreciate your help.  I will look over your example vi.  I made a lot of progress today on my own.  It turns out the sticker with the pinouts for my board was not the correct one for the board I purchased.  After figuring that out I was able to connect to the AFPI 0 terminal and it works great now.  I will be requesting a new pinout sticker for future use and the benefit of others that may use the board after me.

As a side note, I have to use an analog trigger due to the application and set up of the equipment.

Thank you.

[Justin_M]

velho,

Wow...having the wrong pinout sticker is one of those things I would never think to check!  Those are always the most fun issues to troubleshoot .  I'm happy to hear you got it working though, and good luck with your applications!

Justin M

National Instruments