LabVIEW
update value in subVI from main VI
Solved!
I have a subVI that loops for an indeterminant amount of time (at least a few seconds) while polling a piece of hardware for data. I want to let the user stop the polling loop prematurely from the main VI.
I thought I would be able to create a reference to the control that stops the polling loop in the subVI and use that reference with a property node to stop the polling loop from the main VI. But that does not work because when I create a reference on the subVI and copy/paste it into the main VI, it creates a new control on the main VI and the reference no longer refers to the control in the subVI.
I've attached simplified examples that demonstrate the problem. Any ideas?
I would feel more inclined to use a Notifier to stop the subVIs. You "obtain" the Notifier in the top level VI and pass the reference down to the subVIs. The subVIs can then Wait On Notification with a timeout (this can replace your wait). The top level VI can then send the notification to tell the subVIs to stop.
@crossrulz wrote:
I would feel more inclined to use a Notifier to stop the subVIs. You "obtain" the Notifier in the top level VI and pass the reference down to the subVIs. The subVIs can then Wait On Notification with a timeout (this can replace your wait). The top level VI can then send the notification to tell the subVIs to stop.
Yes, that works perfectly. Here is the updated code (for posterity).
I make it even simpler. Set the data type of the Notifier to a boolean. You can then wire the stop condition straight to the output of the Wait On Notification.
The simplest modification of your original vi would be to wire the reference to a subvi input and read its value via a property node there.
Still, if this will be part of a large, scalable project, there are probably better ways.
