Counter/Timer

[Richard_M]

Hi,

I'm using the example vi, 'Gen Dig Pulse Train-Continuous-Pause Trigger.vi' which works fine, but when paused, the pulse train sometimes stays high. I guess it just stops when the trigger occurs. Is this normal?

What I need is for the pulse train to always go low when the trigger happens. I've looked in the trigger property node but can't find anything that may help. I'm assuming the idle state on Create Channel only applies at the start, not after a trigger.

Is there a simple mod to the example or do I need to start again?

Hardware is USB-6221.

Thanks,

Richard Marsden

[Prashant M]

Hi Richard,

I hope you are well.  Thank you for your message.  Your application sounds very interesting.  I have found some useful material that are in the links below that I think you will find useful.  

Finite Pulse Train Generation Triggered by Both Rising and Falling Edges of a Trigger Pulse Using An...

Creating a Delayed, Retriggerable and Finite Pulse Generator

Creating a continuous train of square pulses with a low duty cycle and a controllable voltage and fr...

Triggered Pulse train generation 6602

If you could try these suggestions and let me know how you get on, that would be great!

Kind regards,

Prashant M
Applications Engineer
NI UK & Ireland

[Richard_M]

Prashant,

Thanks for your help. I have managed to do what I required using change detection on the IO and a case statement to either start or stop the pulses, but I'm not 100% happy with what I've done so I'll look at all of your sugguestions, I'm sure there's a better solution to mine.

Thanks again,

Richard M

[univer_solar]

Hi Richard M,

I also have the same problem as yours. I want to the PWM immediately to low when the external signal change from high to low. Would  you please tell me how to do?

Now my PWM can work with the external synchronized signal. It's fine if the PWM is low but when the PWM is high, it pause and still keep the high value that I do not expect.

Thanks in advance.