KUKA Robot codes
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KUKA Robot Controller

System · Basic

Alarm KRC0851

KUKA Robot KRC0851 - BLOCK NUMBER MUST BE POSITIVE 2187

This alarm indicates that a block number parameter used in a KRL program instruction must be a positive integer value. The block number references a specific code segment or jump target and cannot be zero or negative. This validation error prevents execution of instructions that require valid positive block number references.

KUKA RobotSystemBasic

KRC0851

KUKA Robot KRC0851 - BLOCK NUMBER MUST BE POSITIVE 2187

BLOCK NUMBER MUST BE POSITIVE 2187

This alarm indicates that a block number parameter used in a KRL program instruction must be a positive integer value. The block number references a specific code segment or jump target and cannot be zero or negative. This validation error prevents execution of instructions that require valid positive block number references.

Common Causes

  • Block number parameter set to zero or negative value in GOTO or CALL instruction
  • Uninitialized variable used as block number argument
  • Incorrect variable type or data conversion resulting in non-positive value
  • Expression or calculation producing zero or negative result when positive block number is required
  • Copy-paste error or typo when specifying block number literal value

Troubleshooting Steps

  1. 1Locate the instruction flagged in the KRL program source code around the error line reference
  2. 2Verify the block number parameter is explicitly defined as a positive integer constant or valid variable
  3. 3Check that any variables used for block numbers are initialized with positive values before use
  4. 4Review variable declarations and ensure correct data types are assigned for block number parameters
  5. 5Test the program logic to confirm expressions or calculations never produce zero or negative values
  6. 6Correct the block number to a valid positive integer and recompile/download the program to the robot

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