Delayed triggering on DAQCard-AI-16E-4

[jching]

I am trying to learn how to use the counter gate to control a delayed trigger, but having a hard time. I'm using the "Delayed HW analog triggered data acq.vi" and modifying it, but with no sucess.

I have one analog signal(10V) 1mscoming into at 60ms intervals that I wanted to trigger the counter to start. Count for 600us and then use the PFI0 trigger to acquire data from ACH0-5.

I've hooked up the analog trigger to GPCTR0_GATE and the GPCTR0_OUT to PFI0. Now, I'm not sure how to setup the VI to do what I want, and if it's even possible.

Can anyone help?

Thanks

[Nick-W]

First, since your trigger signal is 10V, you must hook it up to PFI0. Sending 10V into a counter gate can damage the counter (as it is only designed to take 5). Unless you are wanting to take a new set of data every 60 mS, you should not need to modify the Delayed HW analog trigger vi that you have.
If what you want is to get a new set of data each time a new trigger comes in, you will need to set things up a little differently. One way to do this would be to configure the counter to do retriggerable finite pulse train generation (see finite pulse train (daq-stc).vi example that ships with NI-DAQ). You would use ATCOUT as the gate for the counter (as shown in Delayed HW trigger example) and use the output of counter 0 as your SCANCLOCK (see Externally clocked examples th
at ship with NI-DAQ).
By doing this, each time a trigger comes in on PFI0, the counter delays a specified amount and then generates a specific pulse train that is the SCANCLOCK to gather the data. When the pulse train stops, the data acquisition stops.

Nick Wilson
Application Engineering
National Instruments
www.ni.com/ask