Error -65536 or -65589 Occurs When Deploying Scan Interface Applications

Updated Dec 9, 2022

Reported In

Software

  • LabVIEW
  • LabVIEW Base
  • LabVIEW Full
  • LabVIEW Professional
  • LabVIEW Real-Time Module

Issue Details

I am developing a standalone LabVIEW Real-Time application which is using the Scan Interface, but whenever I try to deploy the application I receive the following errors:
  • error -65536: Occurred at Shared Variable in XXX.vi
  • error -65589: Occurred at Shared Variable in XXX.vi
 
Why do these errors occur, even if I am not using Shared Variables?

Solution

When developing applications with Scan Interface, the Scan Engine does not load instantly on the target. If the Real-Time application tries to access inputs or outputs before the Scan Engine is running, error -65536 or error -65589 will be thrown and the application will close.

There are several ways to overcome this:
  • Introduce a fixed delay in the initialization stage of the application which will wait up to 10 seconds before trying to access any inputs or outputs.
  • Develop a simple VI that will read an input variable and check the error coming out from the I/O node in a while loop. Only stop the while loop if error code is simultaneously not equal to -65536 or -65589, or a defined amount of time has passed (to avoid iterating indefinitely). An example of this implementation is attached below.