Performance of dedicated PC with ETS RTOS and DAQ

[jbornins]

Hi all,

I'm looking for an inexpensive solution to a fairly simple control problem.  In principle, it seems like running ETS RTOS on a dedicated PC with a multifunction DAQ is the way to go.  However, I'm having trouble finding performance data for this sort of configuration, particularly achievable PID loop rates.  While I understand that this will depend heavily on the PC used and the exact control scheme, among other things, I was hoping that somebody out there would have some ball-park numbers.  I'm also wondering if any of you have experienced pitfalls I should be aware of before embarking on this path.

To narrow things down a little, my application calls for monitoring 3 A/D at >~1KS/s.  One or more of these channels will be used in a control loop to generate the PWM feedback signal, with a loop rate of >~100Hz.  (This isn't a motion controller, and I'm not sure if the control will be strictly PID.)  I'm hoping to run 10 such loops simultaneously (30 A/D and 10 PWM total).  I've preliminarily chosen the PCI-6224 M-series DAQ (250KS/s, 32 Analog inputs).

Thanks in advance for any input!

Jim

[Efosa O.]

Jim Hello.

I am not sure what kind of PID loop rates you can/will get with a Desktop ETS, however, you are absolutely correct that it will also depend highly on your system.

What I can provide you with is a link to our PXI page where you will find different performance specs and hopefully these will give you a ball-park figure of what you can achieve with a desktop system. Just click on the different PXI controllers to the left of the page and each should have the specs and a figure for the PID loop rate.

Please keep us posted if you have further questions.

Efosa O.
NIAE