Function module not working when used with 'In Background Task'

Question

hi,
this is my code
call function 'Z_IBD_FILL_ZINETACT'
              in background task
              destination  'SAPD220125'
              tables
                  it_net1 = it_net1
                  it_net2 = it_net2
                  it_net3 = it_net3  .
when this code is executed i am not getting any data in my internal tables i.e it_net1, it_net2, and it_net3
but i changed this code see the below code
      call function 'Z_IBD_FILL_ZINETACT'
             in background task (THIS IS COMMENTED)
              destination  'SAPD220125'
              tables
                  it_net1 = it_net1
                  it_net2 = it_net2
                  it_net3 = it_net3  .
now i am getting data into my internal tables
can any one tell me what can be the problem and how to solve it in my case
its very urgent

Answer 1

Hi,
Pls. go through the  docu..
CALL FUNCTION
Variant 5
CALL FUNCTION func IN BACKGROUND TASK.
Additions:
1. ... AS SEPARATE UNIT
2. ... DESTINATION dest
3. ... EXPORTING  p1 = f1    ... pn = fn
4. ... TABLES     p1 = itab1 ... pn = itabn
Effect
Flags the function module func to be run asynchronously. It is not executed at once, but the data passed with EXPORTING or TABLES is placed in a database table and the next COMMIT WORK executes it in another work process.
Note
This variant applies only as of Release 3.0, so both the client system and the server system must be Release 3.0 or higher.
Note
qRFC with Outbound Queue
This is an extension of tRFC. The tRFC is serialized using queues, ensuring that the sequence of LUWs required by the application is observed when the calls are sent.
For further information about qRFC, refer to the Serialized RFC: qRFC With Outbound Queue section of the SAP Library.
Addition 1
... AS SEPARATE UNIT
Effect
Executes the function module in a separate LUW under a new transaction ID.
Addition 2
... DESTINATION dest
Effect
Executes the function module externally as a Remote Function Call (RFC); dest can be a literal or a variable.
Depending on the specified destination, the function module is executed either in another R/3 System or as a C-implemented function module. Externally callable function modules must be flagged as such in the Function Builder (of the target system).
Since each destination defines its own program context, further calls to the same or different function modules with the same destination can access the local memory (global data) of these function modules.
Note
Note that a database commit occurs at each Remote Function Call (RFC). Consequently, you may not use Remote Function Calls between pairs of statements that open and close a database cursor (such as SELECT ... ENDSELECT).
Addition 3
... EXPORTING p1 = f1 ... pn = fn
Effect
EXPORTING passes values of fields and field strings from the calling program to the function module. In the function module, formal parameters are defined as import parameters. Default values must be assigned to all import parameters of the function module in the interface definition.
Addition 4
... TABLES p1 = itab1 ... pn = itabn
Effect
TABLES passes references to internal tables. All table parameters of the function module must contain values.
Notes
If several function module calls with the same destination are specified before COMMIT WORK, these normally form an LUW in the target system. Calls with the addition 1 are an exception to this rule - they each have their own LUW.
You cannot specify type 2 destinations (R/3 - R/2 connections).
(See Technical details and Administration transaction.)
Example
REPORT  RS41503F.
/* This program performs a transactional RFC.
TABLES: SCUSTOM.
SELECT-OPTIONS: CUSTID FOR SCUSTOM-ID DEFAULT 1 TO 2.
PARAMETERS: DEST LIKE RFCDES-RFCDEST DEFAULT 'NONE',
            MODE DEFAULT 'N',
            TIME LIKE SY-UZEIT DEFAULT SY-UZEIT.
DATA: CUSTITAB TYPE TABLE OF CUST415,
      TAMESS   TYPE TABLE OF T100,
      WA_CUSTITAB TYPE CUST415.
SELECT ID NAME TELEPHONE INTO CORRESPONDING FIELDS OF TABLE CUSTITAB
               FROM SCUSTOM WHERE ID IN CUSTID ORDER BY ID.
PERFORM READ_CUSTITAB.
EDITOR-CALL FOR CUSTITAB TITLE 'Editor for table CUSTITAB'.
PERFORM READ_CUSTITAB.
CALL FUNCTION 'TRAIN415_RFC_CALLTRANSACTION'
     IN BACKGROUND TASK
     DESTINATION DEST
     EXPORTING
          TAMODE    = MODE
     TABLES
          CUSTTAB   = CUSTITAB.
CALL FUNCTION 'START_OF_BACKGROUNDTASK'
     EXPORTING
          STARTDATE = SY-DATUM
          STARTTIME = TIME
     EXCEPTIONS
          OTHERS    = 1.
IF SY-SUBRC = 1.
  EXIT.
ENDIF.
COMMIT WORK.
CALL TRANSACTION 'SM58'.
      FORM READ_CUSTITAB                                   *
FORM READ_CUSTITAB.
  WRITE: / 'System ID:', SY-SYSID.
  SKIP.
  LOOP AT CUSTITAB into WA_CUSTITAB
    WRITE: / WA_CUSTITAB-ID, WA_CUSTITAB-NAME,
             WA_CUSTITAB-TELEPHONE.
  ENDLOOP.
  ULINE.
ENDFORM.
Pls. reward if useful....