FUN – use function module 

You can call function modules which get values from various application areas for further processing in the test case using the FUN <function module name> function, (see also Using function modules).

1. Enter the function FUN in the Funct. column, and the function module name in the Text column in the function editor.

2. Position the cursor on this line and double-click. You go to the detail maintenance screen, which lists the function module interface parameters.

3. Enter parameter values:

Enter constants, parameters or variables in the fields.

Enter variables and parameters which are to be assigned values by the function module.

If the occurrence of an exception during the run should cause termination, enter "X" in the Value field.

Import

You can only specify one record from this table (not a complete table).

Export

You can only export the header record of this table.

You can check for expected exceptions in the function modules with SY-SUBRC.

You will find the function module interface documentation with the function module (transaction SE37).