Why does a control go to zero when clicking outside of it?

[vilh0005]

I have a moderately high risk test application where I am using a labview program to control hydraulic actuators through PID. Recently when adjusting control parameters, I clicked outside of the control, and it immediately went to zero. This condition has only been replicated three times, and after program restart has not been seen again. I am very concerned this could happen again, and each time it does, it results in a catastrophic part failure. Does anyone know anything about this condition? Your help is appreciated. 

[SteveChandler]

Is anything else in your code writing to the control through a variable or property node? Is it possible that the data entry property for minimum is set to 0 and coerce? If you set a value less than that it will go to 0 when you click outside of the control.

[SteveChandler]

Is anything else in your code writing to the control through a variable or property node? Is it possible that the data entry property for minimum is set to 0 and coerce? If you set a value less than that it will go to 0 when you click outside of the control.

Edit: Weird. I don't know how the double post happened!

[RavensFan]

Normal execution of LabVIEW should not cause this to happen.  Without seeing an example of your code, I can only suspect that you have some race condition by using local variables or property nodes where some other section of code is resetting your control back to 0.

[vilh0005]

Unfortunately, I cannot post code at this time, however it is pretty basic, and there are no variables or property nodes that would force the control. Also, there was no minimum limits set. This is asn intermittent issue.

[Darin.K]

What type of control?

If all that stands between your program and catastrophic failure is a user, you can count on trouble.  Sounds like you need a little range checking in your software.  Added bonus would be method of logging the frequency of these intermittent, and the time stamps can often be traced by back to certain people being in the room....

[vilh0005]

There is range checking in place, and logging. I personally had this happen to me, and another one of my techs did as well on an entirely different control.

[vilh0005]

Sorry, I did not specify control. It is a simple numeric input control.

[Yamaeda]

Is it a Integer/Unsigned numeric control?

/Y

[vilh0005]

It is double.