Message: No global definition found for VAR_EXTERNAL '<variable name>'
Possible error cause: An attempt is made to declare a variable in VAR_EXTERNAL which does not exist in VAR_GLOBAL.
Error correction: Make sure that the identifiers match.
Example of the error:
PROGRAM PLC_PRG VAR_EXTERNAL i : INT; END_VAR VAR_GLOBAL ig : INT; END_VAR --> C0237: No global definition found for VAR_EXTERNAL 'i'