Chapter 15 Application Control
BridgeVIEW User Manual 15-2 © National Instruments Corporation
What is the VI Server?The VI Server is a G programming mechanism that lets you
programmatically control properties and the execution of VIs.
You can use the VI Server to open, call, and close other VIs dynamically,
and to manipulate VI properties. The VI Server is used from the Open VI
Reference, Invoked Node, and Close Application or VI Reference
functions in the Application Control menu. You can use the VI Server
Property Node, found in Functions»Application Control palette, to
control the opening and closing of the front panel of the called VI. You also
can pass parameters to and receive data from the VIs you call dynamically.
All the VI Server functions use error cluster inputs and outputs to make
error handling easier. For detailed information about the Server functions,
refer to the BridgeVIEW Online Reference by selecting Help»Online
Reference, or by right-clicking on the VI Server function and select Online
Help.
As you develop larger BridgeVIEW applications, you might find it
inconvenient to have all of the subVIs in memory at once. For example,
assume you have written a number of VIs that act as user interfaces (HMIs)
for several subsystems within your process. One solution might be to have
a top-level VI that has each of these subVIs in its diagram. The top-level VI
serves as a menu from which you choose the subVI to run, as shown in the
front panel portion of the illustration below.
This VI contains a set of Booleans such that when the user presses a button
on the front panel, the proper subVI is executed. The diagram builds an
array of Booleans and checks the array for any TRUE values. The index of