To call a function module, use the CALL FUNCTION statement:
CALL FUNCTION <module>
[EXPORTING f1 = a 1.... f n = a n]
[IMPORTING f1 = a 1.... f n = a n]
[CHANGING f1 = a 1.... f n = a n]
[TABLES f1 = a 1.... f n = a n]
[EXCEPTIONS e1 = r 1.... e n = r n [
ERROR_MESSAGE = r E]
[OTHERS = ro]].
...
If you specify of ERROR_MESSAGE in the exception list you can influence the message handling of function modules. Normally, you should only call messages in function modules using the MESSAGE ... RAISING statement. With ERROR_MESSAGE you can force the system to treat messages that are called without the RAISING option in a function module as follows:
Messages of classes S, I, and W are ignored (but written to the log in a background job).
Messages of classes E and A stop the function module as if the exception ERROR_MESSAGE had occurred (SY-SUBRC is set to <r E >).