What causes KUKA Robot alarm KRC0904?

Attempting to assign an incompatible complex data type (STRUCT, AXIS, FRAME, etc.) to a primitive variable. Using an array or structure as a left operand where a scalar value is required. Incorrect variable declaration or typo in variable name causing reference to wrong type. Attempting arithmetic or logical operations on non-primitive data types. Mixing incompatible user-defined types in assignment or comparison operations.

How do I fix KUKA Robot alarm KRC0904?

1. Review the line of code generating the error and verify the left operand data type matches the right operand or operation requirement 2. Check variable declarations in the program to confirm correct type assignment for all objects involved 3. Ensure you are not attempting to assign complex types (AXIS, FRAME, ROBOT, etc.) directly to INT, REAL, BOOL, CHAR, or ENUM variables 4. Verify that array indices and structure member access are correctly specified if working with compound data types 5. Use explicit type conversion functions if intentionally converting between compatible types 6. Consult the KRL data type compatibility matrix in KUKA documentation and rebuild/recompile the program after corrections

KUKA Robot codes

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KUKA Robot Controller

System · Basic

Alarm KRC0904

KUKA Robot KRC0904 - LEFT OPERAND NOT EQUAL TO INT, REAL, BOOL, CHAR, ENUM 2241

This alarm indicates a type mismatch in KRL code where the left operand of an operation is not compatible with the expected primitive data types (INT, REAL, BOOL, CHAR, or ENUM). The compiler encountered a left-hand value that cannot be used with the operator or assignment being attempted.

KUKA RobotSystemBasic

KRC0904

KUKA Robot KRC0904 - LEFT OPERAND NOT EQUAL TO INT, REAL, BOOL, CHAR, ENUM 2241

LEFT OPERAND NOT EQUAL TO INT, REAL, BOOL, CHAR, ENUM 2241

Common Causes

Attempting to assign an incompatible complex data type (STRUCT, AXIS, FRAME, etc.) to a primitive variable
Using an array or structure as a left operand where a scalar value is required
Incorrect variable declaration or typo in variable name causing reference to wrong type
Attempting arithmetic or logical operations on non-primitive data types
Mixing incompatible user-defined types in assignment or comparison operations

Troubleshooting Steps

1Review the line of code generating the error and verify the left operand data type matches the right operand or operation requirement
2Check variable declarations in the program to confirm correct type assignment for all objects involved
3Ensure you are not attempting to assign complex types (AXIS, FRAME, ROBOT, etc.) directly to INT, REAL, BOOL, CHAR, or ENUM variables
4Verify that array indices and structure member access are correctly specified if working with compound data types
5Use explicit type conversion functions if intentionally converting between compatible types
6Consult the KRL data type compatibility matrix in KUKA documentation and rebuild/recompile the program after corrections

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