You can use the following template in the definition part of your function module:
IMPORTING IM_PARAM1 TYPE ANY IM_PARAM2 TYPE REF TO <ref_type> EXPORTING EX_PARAM_1 TYPE ANY EX_PARAM_2 TYPE REF TO <ref_type> CHANGING CH_PARAM TYPE ANY TABLES TAB_PARAM TYPE STANDARD TABLE EXCEPTIONS EXCEPTIONS_VALUE.