Calling an Event Based DLL From LabVIEW Causes a Hang

Updated May 3, 2018

Reported In

Software

  • LabVIEW

Issue Details

I have an event based dll that runs as intended as a stand-alone application. When I attempt to call this dll with a Call Function Library Node in LabVIEW, this causes LabVIEW to hang and become unresponsive. How can i use an event based dll with LabVIEW?

Solution

The best way to interface with an event based dll is to configure the application so that the dll posts events to a LabVIEW event structure. With this architecture, LabVIEW will poll the dll at a specified interval to see if an event has triggered. Once an event is triggered, the event structure in LabVIEW will run and operate the code inside of the event structure.
 

Additional Information

Issues can occur when the dll attempts to run code in additional threads. Be sure to put all code in the main thread of the dll.

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