What causes KUKA Robot alarm KRC0901?

Left operand is a BOOL, STRING, AXIS, FRAME, or other non-primitive type when INT/REAL/CHAR/ENUM is required. Array or structure used as left operand instead of a scalar primitive type. Incorrect variable declaration or type casting missing in the assignment. Using a function or method call that returns an incompatible type as the left operand. Copy-paste error resulting in wrong variable being used on the left side of an operator.

How do I fix KUKA Robot alarm KRC0901?

1. Identify the exact line number and variable name from the error message and locate it in the KRL source code 2. Verify the declared data type of the left operand variable matches INT, REAL, CHAR, or ENUM 3. Check if the right operand type matches the left operand type; use explicit type conversion functions if needed 4. Review variable declarations in the DECL section to ensure correct syntax and data types 5. If using array or structure elements, verify you are accessing a scalar member and not the entire object 6. Recompile the program after corrections and verify the alarm code is resolved

KUKA Robot codes

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KUKA Robot Controller

System · Basic

Alarm KRC0901

KUKA Robot KRC0901 - LEFT OPERAND NOT EQUAL TO INT, REAL, CHAR, ENUM 2237

This alarm indicates a type mismatch error in KRL code where the left operand of an operation does not match the expected data types (INT, REAL, CHAR, or ENUM). The compiler cannot process the operation because the variable or expression on the left side of an assignment or comparison is of an incompatible type.

KUKA RobotSystemBasic

KRC0901

KUKA Robot KRC0901 - LEFT OPERAND NOT EQUAL TO INT, REAL, CHAR, ENUM 2237

LEFT OPERAND NOT EQUAL TO INT, REAL, CHAR, ENUM 2237

Common Causes

Left operand is a BOOL, STRING, AXIS, FRAME, or other non-primitive type when INT/REAL/CHAR/ENUM is required
Array or structure used as left operand instead of a scalar primitive type
Incorrect variable declaration or type casting missing in the assignment
Using a function or method call that returns an incompatible type as the left operand
Copy-paste error resulting in wrong variable being used on the left side of an operator

Troubleshooting Steps

1Identify the exact line number and variable name from the error message and locate it in the KRL source code
2Verify the declared data type of the left operand variable matches INT, REAL, CHAR, or ENUM
3Check if the right operand type matches the left operand type; use explicit type conversion functions if needed
4Review variable declarations in the DECL section to ensure correct syntax and data types
5If using array or structure elements, verify you are accessing a scalar member and not the entire object
6Recompile the program after corrections and verify the alarm code is resolved

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