Trigger AI and AO at start of Counter Initial Delay instead of at end ?

[SteveP]

I need to synchronously start an Analog Input AI, Analog Output AO and a single pulse generation Counter task.  I need the option to be able to start these tasks from an external hardware trigger.  The Counter task has a delay before it generates its single output pulse.  This can be accomplished using the Counter's Initial Delay parameter.   The AI and AO tasks can be configured to use a Start Trigger Digital Edge whose Source is the Counter's Internal Output.  This results in the AI and AO tasks not actually starting until after the Counter's Initial Delay.  Is there a way to have the AI and AO tasks begin at the start of the Counter's Initial Delay and not at the end of the Initial Delay (and provide the option for an external trigger to start all 3 tasks) ?

Another counter with an option for external trigering could be used which would start all three tasks but is there a way to just use the one counter ?  I assume a clock starts ticking once the counter task starts in order for the task to know when its initial delay ends.  So could the AI and AO tasks be triggered from that counter initial delay clock ? The Initial Delay time will be variable and on the order of 1 second.

Message Edited by SteveP on 10-16-2008 01:40 PM

[SteveP]

It turns out that using the Counter Source as the Source for the AI and AO tasks instead of the Counter Internal Output will cause the those two tasks to start immediately and when the Counter task starts.

However, in that case an External Trigger cannot be used with the Counter task to cause the AI and AO tasks to wait and to not start until the Coutner task is started because the Counter Source apparently is always running and causes the AI and AO tasks to start immediately.

Message Edited by SteveP on 10-16-2008 01:49 PM

Message Edited by SteveP on 10-16-2008 01:56 PM

[Kevin_Price]

Um, I can't help but think there's something pretty basic that I'm not understanding about your app, but here goes anyway:

Why not configure the AI and AO tasks to trigger off the exact same signal that triggers your single pulse task?  Just have them

all set to trigger off PFI8 or whatever.

-Kevin P.

[SteveP]

External triggering is an option.  Sometimes I need to be able to start all three tasks simultaneously when the user clicks a button.  That can be acomplished by having a second counter generate a pulse with zero Initial Delay.  All three tasks are set to trigger on that second counter's output.