Error -63043 Preventing My cRIO From Timing Out From the Network Connection

Updated Dec 18, 2023

Reported In


  • NI-RIO

Operating System

  • Windows
  • VxWorks
  • NI Linux Real-Time
  • PharLap

Issue Details

I'm getting error -63043 in my LabVIEW program:
Sometimes the remote target (cRIO) loses connection to my network when I get the error message above. I have to manually restart it to make it connect to the network again. How to fix this error?


To prevent this error from occurring, the timeout period for RIO Server RPC connections of the cRIO controller needs to be increased. With NI-RIO 2.3 or later, it is possible to modify these settings manually in the nirio.ini file.
Follow the steps shown below:
  • Locate the nirio.ini file
    • For Real-Time systems, the location of the nirio.ini file varies by RT OS: 
      • On VxWorks and Phar Lap ETS: /ni-rt/system/nirio.ini 
      • On NI Linux RT: /var/local/natinst/nirio/etc/nirio.ini 
    • On Windows systems, the nirio.ini file is stored under the system-wide application data directory.
      • In Windows XP:  C:\Documents and Settings\All Users\Application Data\National Instruments\NI-RIO\nirio.ini
      • In Windows Vista/7/8:  C:\ProgramData\National Instruments\NI-RIO\nirio.ini
        • To access the ProgramData folder, ensure all hidden folders, files, and drives are visible in Windows Explorer.
          • To display all hidden items, within Windows Explorer navigate to Tools»Folder Options»View»Show hidden, files, folders, and drives
    • Note: In case you can't locate the nirio.ini file. This is a known issue. Create the file manually or modify the remote access list from the default values or you can (check the following article for more details on the latter).
  • In nirio.ini, increase the following INI settings:
    • [General]
    • RpcTimeout = 15
    • RpcSessionTimeout = 300
    • DeviceDiscoveryTimeout = 10
      • Note: These values are the defaults and are in seconds (e.g. 300 means 5 minutes).
      • Refer to the Additional Information section for more explanation of these settings
There are many reasons which may lead to this error. If editing the timeout values doesn't take an effect, please check the following article for further troubleshooting.

Additional Information

Caution! Changing timeout values can be dangerous:
The RPC timeout values are not configurable in MAX because they are rarely needed and advanced settings. Care must be taken when setting these values because if they are set too low, communication may fail because targets will begin timing out. If they are set too high, targets that are down will take too long to timeout.

Nirio.ini settings' descriptions:

  • RpcTimeout is a setting on the client-side, which is the maximum amount of time it can take to make a connection to a remote server.
  • RpcSessionTimeout is a setting on the client-side, which is how long the remote server will wait without hearing a "keep-alive" notification before closing the connection. The client will send a keep-alive every RpcSessionTimeout/2 seconds. 
  • DeviceDiscoveryTimeout is how long we will wait for remote systems to respond when querying for remote devices in the Browse window of the RIO I/O Control.