Error in NT Client.vi

[William Kunkel]

I've written some vision code that will run on the driver station computer and communicate with the robot via Network Tables. Whenever I start the VI, I get this error:

Error 1 occurred at Wait on Notification in NT Client.vi->target-detection.vi

Possible reason(s):

LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.

If I select "Continue", the program behaves as expected and communication works fine, but I'd like to know if I can stop this error from occurring. The only inputs I've given to NT Client.vi are Server IP Address (10.4.22.2), Automatic Restart (T), and Update Time (20). The error seems to be related to the "Cancel Ref" input, but I don't know what that does, and I can't find any documentation.

[Greg McKaskle]

Hmm. It looks like this is caused by the reference to the cancel notifier. The wires for error I/O are unwired.

If you open the Bind icon, you'll see that this is given a notifier which is fired whenever we start or stop the playback feature. If you ignore the error, it will not be cancelable, and that should be fine.

Greg McKaskle

[William Kunkel]

Is there any way to suppress the error?

[William Kunkel]

I've got something that I think works. If I wire a "false" constant into the element data type of Obtain Notifier, and then wire the notifier out into Cancel Ref, that stops the problem. Does that have any other consequences I'm not seeing?

[Greg McKaskle]

The client code has been pushed down and the dashboard is using Bind. You could use bind instead, or you can pass in the notifier ref into it like Bind does.

You could also fix the bug in the Client VI. Wire the error out from Notifier Wait into the Notifier Send and wire that output into a Clear Errors function.

See attachment.

Greg McKaskle