Configure Event Callbacks in test stand using labview

[Gops]

Hi,

I was going through Full OI - Configure Event Callbacks.vi in the test stand example. Can you please explain me how the vi works and what is techniwue behind it?

When i open the individual VI's in the reference, I could see more that 1 control in the front panel. But Only the user parameter is wired in the vi? Why is it so?

Regards

Gopal

[AEDavid]

Hi Gopal,

When the TestStand Engine fires events, this VI specifies how your Operator Interface will respond.  For example, let's examine the first event callback registered in Full OI - Configure Event Callbacks.vi , Exit Application.   When the TestStand Engine receives the message to shutdown, and then finishes its neccessary shutdown procedures, it will send a message to the Operator Interface.  For the Operator Interface to receive this message, it must "listen" for it.  In LabVIEW, this is done by Registering an Event Callback.  See the links below for details on how to implement this. 

The answer to your specific question is in step 7 of the first link below.  When TestStand sends the message to LabVIEW, there is information that is always passed.  The other input controls contain this information.  To create a VI that always includes these controls, right-click on the VI Ref input to the Reg Event Callback Property Node, and then select Create Callback VI.

Here are two references that talk about handling ActiveX callbacks in LabVIEW in general:

Registering and Handling .NET and ActiveX Events

Register Event Callback (Not in Base Package)