Jump to content

PID control w/ USB DAQ devices

Recommended Posts

Does anyone have any opinions on using one of NI's USB DAQ devices for PID control? We have a customer that might need to move from an E-series PCI card to a USB option. I have used PCMCIA cards in the past and have not been happy with the performance, but have never used a USB device before. I'm looking at the USB-6221 in particular, but would like to hear any opinions on CompactDAQ as well. Thanks.

Edit: The PID loop rates are on the order of 5 Hz.

Link to post
Share on other sites

Ideally, for closed-loop control, you want a real-time platform that gives you consistent, deterministic performance, like cRIO or cFP. Having said that, "real-time" is a relative term; 5 Hz is within Window's ability to stay fairly consistent in timing, so pretty much any DAQ product should work OK. Not sure why you haven't had good results with PCMCIA in the past -- there's nothing intrinsically limiting in that platform for a relatively slow application like this.

Link to post
Share on other sites
  • 3 weeks later...

I don't think the USB modules have an internal timer, so the timestamping will come from the OS anyway. As mentioned, it can be used to do this, but it depends on the speed and the determinism (which you can't get in Windows anyway).

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.