why isin't SCXI 1160 working as expected with daqmx?

[Ariel]

I'm trying to read and write to the SCXI 1160. I'm useing semaphores so it doesn't happen simultaniously.

Once in a while, several lines get updated (incorrectly) instead of a single one. It happens sporatically, and not always to the same lines. I've found it when I click through a couple times, scrolling through both the lines and the action to the line.

Is there something about my code that causes this?
Thanks very much...

[Ariel]

Sorry, this isin't the answer. realized that the above file attachment won't work, here's one that will...

hope i still get an answer to this...

[Ariel]

Here's the file with all the channels in a config file.

[Brooks W.]

Hi Ariel,

What do you mean when you say, �I�ve found it when I click through a couple of times�?� Do you get any error messages? I would suggest trying to simplify your code (for testing purposes) to determine what portion of the code is causing the problem. Then, we can focus in on the problem. At this point the code is so large that it is hard to pinpoint the problem. When you have done this, give me all the details that you can find.

Have a great day!
Brooks W.
National Instruments

[Ariel]

what I mean is this, when I write an array of T/F to the relays, the written array is correct. The positions of these same relays are read every 100ms . *Sometimes* when I write values to the relays, the positions of the relays subsequently read back are incorrect. I've confirmed with an array of LED's that the relays are not actually switching, just DAQmx read is reading the incorrect relay position.

for example, the Daqmx read returns an array that says the 2nd, 3rd, 5th, 6th, and 7th relays are closed. (right after I tell the 7th, and only the 7th, relay to close) but, I'll be looking at an array of LED's that says only the 7th relay is closed, not any of the others.

And, no, there are no error messages I've seen.

Thanks very much for help...
Ariel

[Ariel]

Here's a more clear example of what I think the problem is. If you open Relay Trouble v3.vi, open/close various relays.

When you get to the 'upper' 4 bits (Release 5 and Damper Heater) you'll see the lower 8 bits are updated to either a single value of on of the upper 4 bits, or the sum of some or all of the upper 4 bits. what it's set to changes seemingly randomly.

This is shown graphically by the changing and strange patterns in the 2D boolean array on the screen.

Thanks for your help, this is killin me...