KUKA Robot codes
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KUKA Robot Controller

Safety · Basic

Alarm KRC0459

KUKA Robot KRC0459 - <string> VARIABLE WRITE PROTECTED IN MODULE <string> LINE <string>

This alarm occurs when a program attempts to write or modify a variable that has been declared as write-protected within a KRC program module. Write-protected variables are typically system variables, constants, or variables explicitly marked with the PROTECT keyword to prevent unintended modification during program execution. The alarm identifies the specific module name and line number where the write violation was attempted.

KUKA RobotSafetyBasic

KRC0459

KUKA Robot KRC0459 - <string> VARIABLE WRITE PROTECTED IN MODULE <string> LINE <string>

<string> VARIABLE WRITE PROTECTED IN MODULE <string> LINE <string>

This alarm occurs when a program attempts to write or modify a variable that has been declared as write-protected within a KRC program module. Write-protected variables are typically system variables, constants, or variables explicitly marked with the PROTECT keyword to prevent unintended modification during program execution. The alarm identifies the specific module name and line number where the write violation was attempted.

Common Causes

  • Attempting to assign a new value to a system variable or constant that is read-only
  • Variable declared with PROTECT keyword being modified in program logic
  • Incorrect variable scope or attempting to modify parameters passed by reference as constants
  • Writing to predefined KUKA system variables (e.g., $ADVANCE, $BASE, $TOOL) without proper authorization
  • Legacy code or copied program containing assignments to write-protected variables from different controller firmware versions

Troubleshooting Steps

  1. 1Review the specified module and line number to identify which variable assignment triggered the alarm
  2. 2Check the variable declaration to confirm if it is marked with PROTECT keyword or is a system-reserved variable
  3. 3Verify program logic to determine if the write operation is necessary or if an alternative approach should be used
  4. 4If the variable must be modified, remove the PROTECT keyword from the declaration or use a different writable variable as an intermediate
  5. 5Consult the KUKA KRC programming documentation or variable reference to understand if the variable is system-protected and cannot be modified
  6. 6Clear the alarm using the teach pendant and recompile/reload the program after making corrections, then test in T1 mode before production run

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