topic Re: Error 1 at Generate User Event in LabVIEW

Error 1 at Generate User Event

Chuck60148 — Thu, 27 Sep 2012 18:44:42 GMT

I am trying to develop an application to turn 3 air valves on and off with time in between activations using a process that runs in the background. I am attempting to use user events to communicate to the background process which sequence of actuations to run at a given time. The problem I have run into is that I get error 1 from the generate user event function in the main program loop. I have read through all of the Nuggets, help files, and discussion posts I can find and I think that I understand how user events work and how to implement them. Or I thought I did. I can't find the issue in this program.

Can anyone help?

I have attached the project folder (zipped). The main program is called Black Hole Control, and the process loop that would run in the background is called sequence.

Thanks in advance,

Chuck

Re: Error 1 at Generate User Event

vt92 — Thu, 27 Sep 2012 19:13:19 GMT

It looks like you are generating a user event before you create the event.

By the way, nice architecture.

Re: Error 1 at Generate User Event

vt92 — Thu, 27 Sep 2012 19:16:23 GMT

I made a slight change to your sequence and the error seemed to go away.

Re: Error 1 at Generate User Event

Chuck60148 — Thu, 27 Sep 2012 21:10:59 GMT

Can't believe I missed that. I must need a break from this. Now that the error is gone, what would prevent the event structure from picking up the generated event? I can watch the data flow through the generate event function (it's a little annoying not being able to verify that an actual event is generated), but the event structure never seems to notice.

Re: Error 1 at Generate User Event

Matthew_Kelton — Thu, 27 Sep 2012 21:18:42 GMT

Which event? The code you posted only appears to handle one of the three events you created.

Re: Error 1 at Generate User Event

Chuck60148 — Thu, 27 Sep 2012 21:37:13 GMT

The '<StateCtrl>: user event'. I have not implemented the others yet. I want to get this one working first as I consider it to be the most important one.

Re: Error 1 at Generate User Event

Matthew_Kelton — Thu, 27 Sep 2012 21:40:04 GMT

The code you posted has Timer Status setup for a user event. Have you changed this?

Re: Error 1 at Generate User Event

Chuck60148 — Fri, 28 Sep 2012 12:21:45 GMT

Yes. I decided that using a reference to the LED indicators would link the indicators more closely to the timers. The StateCtrl & ProgramStop user events are still used. Also, I have not yet coded a generate event function for either of the other 2 user events, I am trying to get the StateCtrl event working first since it is the most important event.

Re: Error 1 at Generate User Event

Matthew_Kelton — Fri, 28 Sep 2012 12:26:04 GMT

Can you post the updated code so someone can see if they can reproduce the behavior you're seeing?

Re: Error 1 at Generate User Event

Chuck60148 — Fri, 28 Sep 2012 15:18:36 GMT

Here is the latest version of the code...

Re: Error 1 at Generate User Event

Matthew_Kelton — Fri, 28 Sep 2012 15:47:49 GMT

I don't see where you are handling the event in your code. You have code that generates the events, but the event structure hasn't had the cases setup for those user events yet.

Re: Error 1 at Generate User Event

Chuck60148 — Fri, 28 Sep 2012 15:54:05 GMT

Look at the vi called 'Sequence'. I am trying to generate the event in one VI (Black Hole Control) and handle it in another (Sequence).

Re: Error 1 at Generate User Event

Matthew_Kelton — Fri, 28 Sep 2012 17:10:51 GMT

So, I see where you kick off the Sequence VI to run, but you never pass the Event refnum to the VI (Process: Begin).

Re: Error 1 at Generate User Event

Chuck60148 — Mon, 01 Oct 2012 18:41:20 GMT

OK, I added a reference item to the valves object and stored the event reference there in the Black Hole Control VI (Image 1a), then I added a register state to the Sequence VI to register the reference with the event structure (Image 2a). I still get no response from the event structure when I generate a user event. The only thing I can think of now is that there may be a timing issue. Could that be the case?