Sync ctr1 to ctr0 (generating freq outputs) via export signal

[groz]

I need help with configuring the counter output channels on my pxi-6723 card. Here is what I'm trying to do:

- have the ability to sync ctr1 output to ctr0. Note: ctr1 must start on rising or falling edge of ctr0 output.

- be able to change idle, freq..etc for each of these outputs

Attached is a sample I've been working on. It works except the ctr1 output is lagging by 1 to 1.5 cycles (depending on idle state,edge selections). This lag is caused by me having to put the slave (ctr1) run task after the master's. Note: The reason for this was the run task of crt0 (master) was causing false triggers when exporting the trigger signal.

Its there a way to software trigger ctr0 OR hold off its output until both (ctr0 & ctr1) "run tasks" have been launched ?

[Brad_K · Accepted solution]

Hi groz,

I haven't tried it, but I would expect the following sequence to prevent the false triggers:

DAQmx Control Task(ctr0 task, Commit)

DAQmx Start(ctr1 task)

DAQmx Start(ctr0 task)

Committing ctr0 should set it to its idle state.

Also, I think you can do this triggering without using a PXI_Trig line. For Start.DigEdge.Src on the ctr1 task, specify "Ctr0InternalOutput". (To make the Ctr0InternalOutput terminal show up in a DAQmx Terminal I/O constant, right click on the constant, select "I/O Name Filtering...", and put a check next to "Include Advanced Terminals".)

Brad