Error 65536 In LabVIEW Real-Time

Updated Jan 20, 2023

Reported In


  • CompactRIO Chassis


  • LabVIEW Real-Time Module

Issue Details

Why do I see the following error when I try to run an example real-time VI or my own real-time code?

Error 65536 occurred at an unidentified location

Possible reason(s):
CompactRIO (Hex 0x10000) Unable to communicate with the module. Reinsert the module and check connections.


Check for the following possible solutions:

C-Series module and cRIO mode incompatibility

  • Reinsert the module and check connections.
  • If the chassis is in FPGA Interface programming mode, make sure you have opened an FPGA reference to a bitfile or FPGA VI with Scan Interface support for the module you are trying to access using the Scan Interface.
  • If the module you are trying to use requires Scan Interface mode but your compactRIO target is in FPGA mode, refer to: How Can I Use Scan Engine and FPGA Simultaneously on a CompactRIO (Hybrid Mode)?

C-Series module and Slot configuration incompatibility

  • This error message can appear when a slot in a CompactRIO (cRIO) chassis is configured for a module other than the module currently inserted in the slot. This usually happens when a module that takes a long time to power on is inserted in a slot configured for a fast module.
    • Add a delay of a couple of seconds to the start of the FPGA VI to give the I/O node enough time to detect the module properly. If after doing this you receive an incorrect module error/warning, either reinsert the modules in the correct locations or appropriately change the I/O module setup in the FPGA Project.