Network Variable Callback Functions

All of your network variable callback functions are called on a system thread for better performance. This thread is blocked until the callback function returns, which can block other network variable operations in your program. To prevent deadlocks, you must avoid creating and disposing connections and browsers, reading and writing data, getting or setting connection attributes, and browsing from within network variable callback functions. You should call only the Network Variable Library Data functions, CNVFreeMemory, or CNVGetErrorDescription in your callback functions.

National Instruments recommends that you return from these callback functions as soon as possible to avoid blocking other network variable events and operations. If needed, you can use the PostDeferredCallToThread User Interface Library function to process network variable events in a different thread.