Multiple switches conflict

[Daddy-O]

I have built a control system for 36 doors. They all require that a switch be closed every 30-40 seconds, independent of one another. I am running into issues every hour or so where apparently I am trying to close them at the "same time" and it's locking up my application. I am using a PXI 2569. Is there a way for me to make a connection wait until the card is available? It a 400mS contact I have to make, so when I get ten or twelve doors up and running, the conflict is pretty regular. I am not sure, at all, if this is what is locking up my application, I just know that when I have only a couple of doors running, it happens much less frequently. I don't get an error message or anything, the front panel just goes "inactive" and gray. Please help, boss is FREAKING!!

Thanks. Switch Newbie

[chericks1]

Hi Switch Newbie Daddy-O,

In response to: Is there a way for me to make a connection wait until the card is available?
You can queue up requests by using an event structure in LabVIEW.  After each door operation request is received, the request generated will wait until it can be processed.  Even if it takes 400 ms to process one request, the next will not be lost - rather, it will begin processing immediately after the previous finishes. 

May I ask you to include the switching section of your VI?  I would like to investigate further why the front panel goes "inactive" and gray.  Perhaps there is a substantial portion of the application utilizing the user interface thread?  Please let me know.

Hope this helps!

Chad Erickson
Switch Product Support Engineer
NI - USA

[Daddy-O]

Chad,

It turns out that this wasn't my problem at all. I had placed to short of a "wait" in my DAQ section, that was causing the graued out condidtion. As for the relay conflict. I had structured it properly, like you suggested already. The only time I was getting the conflict was when I was "manually" throwing the relay. My program had already accounted for the possibility of multiple access. The commands are in an arrracy, so they were going to be handled sequentially anyway. This was just a case of me jumping the gun and blaming my architecture rather than keeping it simple when diagnosing.

Thanks for your help!!

PS how do I rate your response? I don't see the place at the bottom that the help talks about!?! Have a great day!!

Chris

[chericks1]

Hi Chris,

Looks like you're good to go.  Glad to see you solved the issue! 

By the way, thanks for providing your advice for our customers in other posts.  We appreciate it.  Keep it up!

Best regards,

Chad Erickson
Switch Product Support Engineer
NI - USA