What is the best way to send out a pulse from the counter output of the DAQ, where the start, stop and pulse-repetition frequency is controlled inside a queued state machine?

[MATCHU]

I have a queued state machine that I am trying to use to control a counter output, as well as some basic analog voltage signal acquisitions on a USB-6211 DAQ. The state machine passes a boolean true to a conditional structure to start the pulse output on my DAQ. The repetition frequency (1-20 Hz) is controlled using a "wait for next millisecond multiple". While the state machine is sending the "go" command over the queue, the pulse output I'm getting has an unacceptable amount of jitter (+/- 5 Hz). Is there a better way to do this where I could at least maintain my repetition frequency within 1 Hz?

That attached VI does not have the oscilloscope driver included.

Thank you,

-Matt

[MATCHU]

UPDATE: I generated the actual code from the DAQ Assistant and set up my VI to change the high/low time values. This gave me a very reproduceable pulse train with low jitter. Now the problem is: I can't find a way to start and stop the pulses from a boolean outside of the DAQ VI I created to do this. Any suggestions?

[chaka1234]

MATCHU,

You can place your DAQ Assistant into a while loop and create a switch button and wire it into the Stop Input from the DAQ Assistant.

Regards,

Carmen C.

Applications Engineer

National Instruments