KUKA Robot codes
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KUKA Robot Controller

System · Basic

Alarm KRC0604

KUKA Robot KRC0604 - Channel already open

This alarm indicates that a software application or process attempted to open a communication channel that is already in use or active. The KRC controller prevents simultaneous access to the same channel to avoid data conflicts and maintain system integrity. This typically occurs in multi-tasking environments or when improper channel closure procedures are executed.

KUKA RobotSystemBasic

KRC0604

KUKA Robot KRC0604 - Channel already open

Channel already open

This alarm indicates that a software application or process attempted to open a communication channel that is already in use or active. The KRC controller prevents simultaneous access to the same channel to avoid data conflicts and maintain system integrity. This typically occurs in multi-tasking environments or when improper channel closure procedures are executed.

Common Causes

  • Application failed to properly close a channel before attempting to reopen it
  • Multiple threads or tasks attempting to access the same communication channel simultaneously
  • Incorrect sequence in channel management subroutines within KRL program logic
  • Software exception or crash that left a channel in an open state without proper cleanup
  • Conflicting device drivers or third-party software accessing the same interface resource

Troubleshooting Steps

  1. 1Stop the current KRL program execution and perform a soft reset of the KRC controller
  2. 2Review the KRL source code to verify proper channel closure using CLOSE() function before reopening channels
  3. 3Check the channel management logic for race conditions or improper exception handling in multi-task environments
  4. 4Verify that all communication channels are explicitly closed in the program's termination routine and exception handlers
  5. 5Clear any residual channel locks by cycling power to the KRC controller if soft reset does not resolve the issue
  6. 6Test the application in single-task mode to isolate whether concurrent access is causing the channel conflict

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