Steps
1. Create variant called BACKGROUND for program(ZTEST0009) to be debugged.
创建一个名为:BACKGROUND 变式
程序:ZTEST0009:
2. Execute ZDEBUGBG (pgm code below) in background for immediate processing.
执行变式
3. Execute transaction SM50.
4. Select process that runs ZDEBUGBG.
5. Goto 'Program/Session' 'Program' 'Debugging'.

A se80 debug session will open.
6. Change variable W_EXIT to 'E'.
7. Step thru (F6) until ZTEST0009 comes up.
*&---------------------------------------------------------------------*
*& Report ZDEBUGBG *
*& *
*&---------------------------------------------------------------------*
*& *
*& *
*&---------------------------------------------------------------------*
REPORT zdebugbg.
DATA:
w_exit TYPE c.
FIELD-SYMBOLS
TYPE ANY.
SELECTION-SCREEN BEGIN OF BLOCK one.
PARAMETERS: p_repid LIKE trdir-name DEFAULT 'ZTEST0009'.
SELECTION-SCREEN END OF BLOCK one.
START-OF-SELECTION.
PERFORM. loop_time.
PERFORM. submit_time.
END-OF-SELECTION.
*---------------------------------------------------------------------*
* FORM. loop_time *
*---------------------------------------------------------------------*
* ........ *
*---------------------------------------------------------------------*
FORM. loop_time.
DO.
IF w_exit = 'E'.
EXIT.
ENDIF.
ENDDO.
ENDFORM.
*---------------------------------------------------------------------*
* FORM. submit_time *
*---------------------------------------------------------------------*
* ........ *
*---------------------------------------------------------------------*
FORM. submit_time.
ASSIGN p_repid TO .
SUBMIT () USING SELECTION-SET 'BACKGROUND'.
ENDFORM.