How do I output PWM in an SCXI chassis

[jbrohan]

Hello
I have a high channel cound data logger / oven system. We have used Fieldpoint very successfully for many years in a similar application. Now there are 40 or 80 ovens to control. There does not seem to be an SCXI PWM module. How do people control heaters with SCXI?

[David L.]

Hi JBrohan,

The ability to do counter/ timer functions with an SCXI chassis depends on the DAQ card you have. Do you have a PCI card (which one)? SCXI-1600? Etc… Your DAQ card must have counters on it, as the SCXI (and modules) do not have counters on them, but pass the signal through to the DAQ card which does. You can then check that the DIO pins match up to the counter pins on your DAQ card.

[jbrohan]

Hi David
Thanks for your reply. This is a new installation and I can order the card to match! Can you recommend one? The SCXI needs to control 32 heaters using PID.  Do you have an example of generating 32 PWM waveforms for an SCXI digital output module?
Yours Sincerely
John

[David L.]

John,

Are your heaters controlled via analog voltage? If so, is there a reason you want to do PWM?

Is there any reason why you are leaning towards SCXI? There are no SCXI PWM modules, and my best recommendations would be to stay with Fieldpoint or use Counter PCI cards. The Fieldpoint has 8 PWM / module, and we have counter cards with 8 counters on a card.

What are the current and voltage your heater draws? I am trying to get a larger picture of what you are trying to accomplish, as this will help in finding the right tools for your project.