Start counter on analog trigger

[DBM]

I have an E-series card and I would like to start a pulse train on a particular level of a rising edge of an analog signal. Specifically, I have a sine wave going from -1V to +1V and I would like to start the pulse train on the rise of the sine from 0V.

Thanks!

[mikeporter]

A very simple approach would be to condition the analog signal to convert it into a TTL-compatable squarewave that switches at the input sinewave's zero-crossing point, and feed the result into a digital input on the card. Just make sure whatever technique you use gives a very clean edge and no over/under shoot or ringing.

Mike...

[DBM]

Mike, thanks for your answer, but I may not have explained things just right.

I'm trying to output an analog signal (the buffered sine wave) and, synchronized with it, a digital trigger signal (the counter). Their relative phase seems to vary with the frequency, so I can't just try to start them together. So I thought of taking the analog signal, feeding it into an analog input and using the analog trigger signal (ATCOUT) to start the counter.

I'm not sure what signals I should set to what values in Counter Set Attribute.vi to achieve this. The closest example is ATCOUT Viewer.vi found in Analog Trigger Circuitry Output as an External Signal.zip, but I don't need to use the double counter.

Thanks!

[RIO-Todd]

Devices that have the DAQ-STC chip don't have the capability of triggering a counter event. You could do this with a NI TIO device but not with a DAQ-STC device. The document below goes over this in more detail. I hope this helps.

Can I Use the AI Start Trigger of the Analog Input Channels to Trigger Pulse Train Generation from the DAQ-STC Counter?
http://digital.ni.com/public.nsf/websearch/80AA17718CFC0A4886256B4A00785103?OpenDocument

Regards,

Todd D.
NI Applications Engineer

[DBM]

Actually, "ATCOUT Viewer.vi" (found in "Analog Trigger Circuitry Output as an External Signal.zip") is exactly what I needed.

Thanks!