How to trigger using CO pulse ticks

[Brus_L]

Hi all,

I'm using a PCI 6251 to build a AI with trigger. I'm using CO pulse ticks. I don't understand the function of high tick and low tick. How are they gonna affect my triggering action if I'm using "Start Digital Edge" and set the idle state to be low? I assume if I set 10000 low ticks and 1000 high ticks, then first it will stay low for 10000*my timebase and then goes to high which triggers my AI. But it seems that no matter how many high or low ticks I set, it doesn't affect my triggering time.

I want to start acquiring signal after a certian time say 1 s. I know I can use delay time option in CO pulse ticks. But can I specify it using ticks?

thanks!

[Brus_L]

Please!

[Mcdan]

Brus_L,

I believe that for your single pulse task, your pulse train will be issued as initial delay followed by high time.  If you're trying to delay your edge, I believe you'll want to do this via the initial delay input.  If you are simply trying to delay AI sampling from when you call DAQmx Start Task, you can use the DAQmx Trigger Property node and set the Start->More->Delay and Start->More->Delay Units property (essentially replace the DAQmx Trigger VI with this property node).  This would effectively accomplish the same thing you're trying to do with your counter task, without needing to use a 2nd task.  I've attached your VI with this modification.

Hope that helps,

Dan