Event case not catching value change EVEN WITH value signalling node

[AGriffiths]

Afternoon all,

Sorry if this has been covered before, but I've spent a while searching the forums and come up none the wiser.

I understand that programmatically changing a front panel object doesn't generate an event unless you use the Val(Sgnl) property note, but why isn't this picking anything up even with one?

There's no other event structure in use, front panel locking is off, and the new value does go to the front panel object - the event structure just doesn't seem to notice.

What am I missing?

Cheers

[aputman]

Nothing immediately sticks out to me when I look at this PICTURE.  If you can post the actual code, we can help more.

I do see a 1 pixel sliver of another loop maybe above the LCD Display Loop.  Is this a hungry loop that is starving out the CPU, preventing the display loop from executing? 

Do you have a loop running in the timeout event that is blocking the event structure?

[AGriffiths]

Full program attached - it's a work-in-progress, so forgive its sprawl!

Short answers though, nothing running at full pace, and nothing else in the timeout structure yet.

[paul.r]

What else is happening in your event handling loop? Is it stuck in another case?

[crossrulz]

Stupid questions:

1. Are you sure that display loop is running?  Did is stop?  Is it stuck in the timeout case for some reason?

2. Are you sure that property node is actually being called?  I see several conditions that could keep it from being written.

3. Is there another "Output" control on your panel that your Event Structure could be registered to?

[crossrulz · Accepted solution]

The myRIO does not have front panels in the RT.  You cannot use the Event Structure or property nodes to do anything.  Use Queues to pass your data between loops.

[AGriffiths]

There's no stupid questions, the number of times I've had an entire project stalled by some tiny error...

The only other thing in the display loop is the timeout case, which just passed the cluster through. Just to be sure, I just went back and added a toggling boolean in there, and I can see it flashing away on the front panel, so it's definitely running.

The actual string being written to the property node IS appearing on the front panel, so that much is working.

No other outputs, although I'll go back and change it to something more unique to be certain. Probably good practice anyway.

[AGriffiths]

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@crossrulz wrote:

The myRIO does not have front panels in the RT.  You cannot use the Event Structure or property nodes to do anything.  Use Queues to pass your data between loops.

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Huh! Well that's a complication. Thanks, I'll have to do some re-writing.

[ikaiser]

Just to back crossrulz correct answer with some facts:

• Event Structure Support in LabVIEW Real-Time
• Unsupported LabVIEW Features on NI Linux Real-Time Targets (myRIO runs NI Linux Real-Time)