LabVIEW
Build Array and Avoiding Buffered Allocations ... a little help here??
Hello,
Where does your VI lock up in the State Machine? Is it locking up in one of the states or is it simply waiting for the queue?
-Zach
Ok, my friend, I've had a look at your code. There are a few problems I see, but to start with, I will go ahead and reveal the Great Secret as to why your User Events queue appears to lock up...
It's not locking up. It's working just fine.
In your code, for some reason that I don't understand, you have a "generate occurrence" function, wired to a "Wait on occurrence" function. Your "wait on occurrence" function does not have a timeout specified, so it'll just sit there and wait and wait and wait until the cows come home (and they're out partying). And that's exactly what it's doing. Just sitting there, waiting (you never actually set an occurrence...you just wait for one). Since three out of your four loops require the output of that "wait on occurrence" function in order to get started (a loop can't start until it has all its inputs), they can't start executing.
Therefore, your event structure loop never even starts. Same with your mysterious timing (?) loop and your DAQ loop. The only one of your loops that's running is the one containing your state machine, and of course it has a "dequeue" function that is set to never time out. So, that dequeue function sits there, waiting and waiting and waiting...just like you told it to. Thus, the program appears to hang. It is not hanging. It is doing precisely what you told it to do.
You might note, in the "wait on occurrence" help, that it specifically says that NI recommends you use notifiers and not occurrences. I second this. Whatever you have that in there for, either give it a timeout so it can execute and be done, allowing your other loops to start, or get rid of it entirely and replace it with another notifier (you can use as many notifiers as you want, just like queues).
Ok. On to your next problem. You have one end of your DAQ queue (the "enqueue" function) placed, appropriately enough, in your DAQ loop. You have the other end of your DAQ queue (the "dequeue" function) placed in the "Data" state of your state machine. However, you never queue in the "Data" state from your UE queue...so when is all that data coming in from the DAQ loop supposed to be dequeued and displayed? Also, if you want continuous dequeueing, you will either need to repetitively enter your "data" state, or you will need to put the "dequeue" function into a loop. Otherwise, you'll keep sending data via that queue and never dequeue it...as happens currently.
Next issue! You do not have a single function which stops all of your loops. In your event structure loop, you can either stop that loop with your eeeeeeevil global, or the "stop" button.
In your state machine loop, you have to queue up the "done" state in order to stop the loop. That's done in a rather roundabout way, but I will assume there's a good reason for that.
In your weird timing loop, you use the eeeeeevil global.
In your DAQ loop, you use a button labeled "stop5". When I click on that terminal to find the control, it's hidden waaaay far away from your other controls, obviously not supposed to be accessible to the user. Unless that button is pressed, that loop is never going to stop. Sure enough, that's exactly what happens, and your program appears to hang. It doesn't really hang, of course...that loop keeps happily executing along, never having been told, "hey, the rest of us are done..."
So, those are the main things you'll need to fix, to start with.
Told you I'm a nightmare... 
d
jonathanupr wrote:...
Also, quick question in regards to the individuals who reply to all these threads on this forum...NI employees? or just altruistic individuals?
Definitely very helpful & unique.
All but zach (the "blue bars" are NI employees) are altruist.
Aren't they something? 
Ben
