Compiler Error C0090

Message: No definition found for base class '<function name>'

Possible error cause: The function block specified as the base does not exist or is not a function block.

Error correction: Use a function block as the base.

Example 373. Example of the error:

PROGRAM PLC_PRG
VAR
     inst : FB;
END_VAR

FUNCTION_BLOCK FB EXTENDS POU
VAR
END_VAR

FUNCTION POU
VAR
END_VAR

Message:

C0090: No definition found for base class 'POU'