Hi I build a small program  before converting it into Sub-Vi.
I have a problem which i can't solve. That's because I am unable to use highlight execution to troubleshoot.
 When I start the program with the highlight execution on. It stopped abrupty popping up a message " Error 1 occurred at release Queue in my file,  Possible reasson: An input parameter is invalid" So what could have gone wrong? How do I troubleshoot it?

So here's my program, read-table.vi

And there's another thing about multicolumn listbox put inside main vi.
But I need to create a subvi (my current read_table.vi) that receives the input and output to multicolumn listbox in main.vi. I would like to program such that the sub-vi will process data and input to main.vi thru multicolumn listbox in REAL TIME, NOT after the subvi has finished before putting all data to main vi. Is there a way?  The read_table.vi will be without multicolumn listbox once it works, so how do i write the data to multicolumn in main.vi from read_table.vi. Should I use control reference?

Clement

Your VIs weren't attached. If you preview a message, you lose the attachment. Also, you can only attach one file. ZIP your files or save them as an LLB and repost them. Also, state which version of LV you're using.

The release queue is giving you an error because it is recieving an invalid queue. Maybe you already released the queue and now it doesn't exist. The error pops because you left the error out output unwired. You should use it to do error handling, but even if you wire it into a sequence structure, the error will stop popping.

You can use a reference for your other request. You need to pass the reference as a control and use the value property in a property node wired to that reference. To do this, right click the terminal and select Create>>Reference, then right click the reference and select Create>>Control. Copy this control (the reference) to the subVI and have it as part of the connector pane. On the BD, wire its terminal into a property node. 
You should watch out for race conditions. Other options include using global variables and functional global variables.

Hi
i m using queue vis first time.I think i m using them correctly but i am not able to stop the VI.
i am sending the VI . If someone sort out the problem then plz tell me
thanxs


Queue.vi:
http://forums.ni.com/attachments/ni/170/197009/1/Queue.vi

Hi
The vi did no terminate, because the dequeue element waits for an element to dequeue for an infinite time.
You have two options:
1. Remove the "wait for ms multiple" function and wire a constant to the timeout of the dequeue function
2. Wire the release queue function out of the loop where you generate the events instead of the consumer loop. In this case the dequeue function is also interrupted.
 Message Edited by becktho on 07-24-2006  10:53 AM

If you have a look at the LV help, you can find that error code 1 occured due to an invalid input parameter.
Run the vi in highlighting mode and observe what's going on in the block diagram. This way you can locate the error and maybe eliminate it on your own or you can give more information about it.

Hi
Thanxs for quick reply.
one more questions - sometimes while running the same vi for the first time i got an error 
Error 1 occured at Enqueue element in Queue.vi
Error code - 1
what is the reason of getting this error.
thanxs
 

The reason is indeed the two errors.
What's happening is this:

- You click the buttons as many times as needed and everything works fine.

- You enter the bottom loop. The stop button is read as F and the loop waits at the Dequeue node.

- You destroy the queue in the top loop. The dequeue node returns error 1122 and 0 (the default value for the DBL data type). The loop does not stop, because the stop button was read at the beginning.

- The loop iterates again. The queue was destoryed, so you get error 1 and 0. Since you pressed the stop button, it is now T and the loop stops.

That's your two 0's.

Hi,          3.  You destroy the queue in the top loop. The dequeue node returns error 1122 and 0 (the default value for the DBL data type). The loop does not stop, because the stop button was read at the beginning.  This error is inevitable? To stop the VI I need release queue, isn't it?4.   The loop iterates again. The queue was destoryed, so you get error 1 and 0. Since you pressed the stop button, it is now T and the loop stops.
I've solved the error 1 (picture), but I think this solution is very dirty.


solution error 1.PNG:
http://forums.ni.com/attachments/ni/170/257300/1/solution error 1.PNG

Great!  Thank you

You don't need to destroy the queue twice. Once is enough and you can then use the error.
Here's an alternative approach.


Example_VI.png:
http://forums.ni.com/attachments/ni/170/257312/1/Example_VI.png