Array Of Clusters Not Initializing or Possible Race Conditions

Question

Hi all,
I've been working on a fairly complex project for work, and I haven't worked with Labview before. Unfortunately nobody in my office really has experience with it so I'm on my own. I've mostly got the project working, and it might be a little cumbersome, but if it works that's fine.
Essentially it's a temperature control device and I made it so it's expandable, thus the clusters and arrays everywhere.
My question is this. I've got an array of clusters indicating the status of all the plates in the system. When I start up the VI for the first time they do not initialize. They just stay grey, but when I stop it and start it once, it will work every time. I think this is kind of strange behavior. I've heard of race conditions and while I've tried to make sure t hat's not happening, it might be without me noticing.
I've tried putting an initialize array block in the first call while loop and that doesn't do anything, and if I remove the initializer from the shift register in the top while loop that stops them being initalized altogether.
I guess I was hoping someone might have an idea what's causing it, or could possible give my code the once over. The main bulk of it is in the very top of the code, but there are a lot of smaller events taking care of GUI type stuff.
I've included all source code. It might be a little much but I didn't want to start pulling it apart if I don't know what's happening.
Thanks in advance.
Chris.
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Attachments:
Error During Cycle Controls.zip ‏3107 KB
Stop Cycle Controls.zip ‏2115 KB
Stop Cycle Controls.zip ‏4975 KB

Answer 1

Chris Johnson wrote:
So just to confirm, I can have one event structure with say 10 events happening? In this case could an event happen simultaneously with another? I thought I read something about each event having it's own event structure and while loop to make sure this works out.
Each event case must complete before it can handle the next event, but many events will complete so quickly that this is not an issue (such as your "pause chart" button).  In general you should have only one event loop.  If you expect an event to take a long time to process, use a queue to hand that task off to another dedicated-purpose loop, so that the event structure can go back to waiting.  This is one example of the producer-consumer structure often mentioned on this forum: the producer is the loop containing the event structure, and it queues (produces) items to process.  A separate loop dequeues (consumes) those items and handles them appropriately.
As GerdW mentioned, you have race conditions all over the place.  You'll never know whether the Plate Info Cluster Array is properly updated because it's being written and read simultaneously in so many places.  I'm assuming that is also where you're seeing the issue that inspired the post, and, in fact, one of those race conditions could explain what you're seeing.
Chris Johnson wrote:
Also, again, to confirm what I think I already know. When the event completes it outputs whatever data you output from the structure and then you can place it in a shift register. Where does this go until the next event takes place?
I don't understand what you're asking.  Where does what go until the next event?  If by this you mean the data in the shift register - it stays in the shift register, accessible at the corresponding terminal on the left side of the loop.