Multiple channel acquisition, and synchronization with output channel

[Prevat]

Hi John,

the stimulus I have to apply ranges between circa -2V / +2V, depending on the application. But I also need to beeing able to adjust the "baseline-" of the pulse. (typical pulse is -60mV that jumps to +20mv for 5 ms).. so I don't think TTL is an option for me...

The idea of using another input channel sounds good to me.. I'll then have to read about 6 channels but I think that 40kHz sampling rate will be fine.

I 'll be very happy if you could write an example for me, it will save me really a lot of time since I'm not very familiar with labview...

again, to answer to your questions:

   -the stimulus isn't TTL (moreover, the DI subsystem is available...)

   -I think that pre-trigger samples would be better me...

I've attached an image where you can exately see what I would like to obtain: Upper corner left is the array containing the stimulus that is sent to the output channel, upper corner right is the aquired stimulus (from the amplifyer, not usable for triggering) and the bigger chart is the answer I get from my system.

I've also attached an extraced part of my VI, where the stimulus is generated and the answer registered (using the finite mode). Said in short words, I need this VI working in continuous mode 😛

P.S. I know the architecture of my VI is bad, but momentairly this is the last of my worries 🙂

Regards and thank you very much,

Prevat.

[John_P1]

Hi Prevat,

Here's an example to get you started that shows one way to implement a reference trigger in software:

The most basic use case for SW Reference Trigger.vi  looks like this:

           

This would implement a reference trigger on a single channel.  If you want to acquire other channels continuously, you would need to split the signal so that you feed only the "finite" channel into SW Reference Trigger.vi.  It is not currently built to allow for triggering from another channel, but this behavior could be added by a slight modification to the VI.

Best Regards,