variable frequency counter output

[labnoob]

I found this example of how to vary the frequency of a counter output, but it appears this is not supported and i receive the following error. Can anyone tell me if there is an alternative method at all? my device is a usb6341 which has 4 COs

thanks

[mikeporter]

If you found that code in an NI-provided example, it's probably more likely that the operation is not supported by your specific hardware.

• What is the range of frequencies you want to create?
• How accurate does the clock need to be?
• How often will the frequency be changing?
• Can the hardware receiving the clock tolerate and "discontinuities" in the pulse train?

You could momentarily stop the clock, change the setting and then restart it.

MIke...

[labnoob]

Hi,

Up to 5hz is all. I'm simulation strokes from piston pumps of which I have 4 to validate an embedded flow meter instrument I have developed. I also would like to instruct labview to inject n number if pulses too. Essentially I need to verify total pulses sent equals total received and also rate calculations

[mikeporter]

So you need to be able to vary the frequency and generate just a specified number of pulses? Is there anyway to structure your test such that it doesn't need to change the frequency in the course of the test?
I'm afraid that with the hardware you have it might not be able to do what you need. It sounds like you need to explicitly toggle the output bit and not with a counter, but between the PC and the USB interface you would have so much latency the test results would probably be useless.
Any chance of getting access to a plugin DIO card or a CRIO system?

Mike...

[labnoob]

Hi Mike,

I had the same thought as a lay in my bed last night. I could programmatically send n number pulses, then restart at a different rate and send another n number pulses

Thanks Mike.