Counter Output

[Alankar]

Hello

I am using DAQ PCI 6221 card for analog inputs and outputs, I am using both the counter outputs for controlling temperature, by putting heaters On and Off through the digital pulse train I am getting from counter outputs.

But I am having a problem with the counters that even if I change the Low time and High Time the pulse I get just dont changes accordingly,

changes timing effects from next time when I run the VI, I am attaching the VIs(CTR1.vi and CTR0.vi are similar just change the channel name) involved in this, first I am acquiring the temperature and then comparing it with low and high limits and taking an action whether to On or Off heaters.

High Time and Low time are required because as soon as I reach near to set temperature I increase the Low time and vice versa.

Could anybody please tell me where I am wrong??

[Rudi_N]

Alankar:

I am having a hard time understanding the issue, are you saying that changing the high and low times does not change the pulses?. Please provide me with more information so that I can help you better.

Thanks,

Rudi N.

[Alankar]

Thanks Rudi for the reply,

Actually I am using a counter output and I have two controls for Low Time and High Time , but when I run the program, if I change these control values the pulse doesnt changes according to these times, I get the pulse as per the time values which were at the starting of the VI.

I hope I am able to define the problem now.

Alankar

[Elijah_K]

Are you trying to change these values once the task has started running?  Consult this KB for information on how to do to this:
"Why Can't I Change the Duty Cycle on My Continuous Pulse Train?"   [link removed; article no longer available]

To summarize, you'll need to use DAQmx channel property nodes to set the pulse width and frequency.

[Alankar]

Thanks Elijah,

Thanks for your reply.

Regards

Alankar