SLU P one-out one-in

This sample program demonstrates using FEPI to obtain information from a back-end IMS system, using SLU P mode and the FEPI CONVERSE command with the POOL option.

Module names

DFH0VZPS, DFH0AZPS

Transaction name

CZPS

Map names

DFH0MZ4, DFH0MZ8

On the first invocation of the program, a map is sent to the front-end terminal.

When there is input from the front-end terminal, CICS reinvokes the program. A simple inquiry is made to the back-end system—for illustration purposes, it asks the time—and the answer is displayed on the front-end terminal. Because the inquiry requires only a one-out one-in exchange with the back-end system, a temporary conversation can be used, so the FEPI CONVERSE command with the POOL option is used.

When PF3 or CLEAR is received from the front-end terminal, the transaction ends. If there is an error, the front-end map is reset. These situations are detected using HANDLE CONDITION.

If the back-end system sends an IMS message, it is sent on to the front-end terminal and the transaction ends.

For clarity, error checking is minimal except for the FEPI commands.

Figure 1. CZPS transaction: SLU P sample program

 CZPS             SLU P Sample Program.
 IMS SLU P conversational sample program
 This transaction will process a FEPI CONVERSE command to obtain time
          and date from a back-end IMS system.
          DATE   :  02/04/92
          TIME   :  10:57:10
          STATE  :  Not started
 F3=EXIT to CICS  ENTER=obtain time and date stamp from IMS

Program logic

  MAIN procedure:
    Test COMMAREA
    If transaction not previously invoked
        Call SEND-NEW-MAP
    Set up exception condition handling:
        Map error - SEND-NEW-MAP
        CLEAR/PF3 - END-PROG
    RECEIVE MAP from front-end terminal
    Build SLU P data stream to request time from back-end IMS
        system
    FEPI CONVERSE to send data stream to the back-end and get
        the message containing the time
    If IMS message received from back-end system
        SEND message to front-end terminal
        RETURN
    Build data for front-end terminal map
    SEND map data to front-end terminal
    RETURN TRANSID(CZPS) with COMMAREA
  SEND-NEW-MAP routine:
    SEND new map
    RETURN TRANSID(CZPS) with COMMAREA
  END-PROG routine:
    Clear front-end terminal
    RETURN