Pwm generation with NI9401 and DAQmx (Labview 8.5.1)

[gmarocco]

I would like to build a variable pwm generator for a motor test (for work purposes) using a channel of NI9401 (the module is inserted into the chassis NIcdaq-9178 (I work with Labview 8.5.1).In order to set-up the module,  I have followed the following tutorial: http://digital.ni.com/public.nsf/allkb/0892C8D55C6D0C0E86257585004FD0B0   However, I have not found in Labview 8.5.1 the option in order to set NI9401. Is it possible to generate a PWM signal with this equipment?

Another question. I would like to change automatically every 0.2s the duty-cycle (the signal has a period of 20ms). Could you give me some hint for this operation?

Thanks in advance

[pep91]

Hello gmarocco,

it may be a problem of driver. Which DAQmx driver do you have installed in your computer? 

Concerning the changing of duty-cycle, you can do it using a while loop with a timing of 0.2 s and each iteration you have to change the time period in which your digital signal stays high. 

Kind regards

[pep91]

PS: check out this document, it could help you to find out how to change the duty-cycle while while your application is running.

http://digital.ni.com/public.nsf/allkb/82C9F3C15F62974E86256EBA0058CAF5?OpenDocument

[pep91]

Anyway, you cannot following the procedure you linked, this is referred to cRIO not to cDAQ.

[gmarocco]

Thanks, I  am using  NI-DAQmx 9.0.2

[pep91]

Can you use your cDAQ with this version of drivers?

Anyway you cannot use this procedure since it is valid just for cRIO devices, not for cDAQ.