The back-end IMS program

This program is the IMS back-end application used by the FEPI sample programs.

This is a simple IMS back-end response mode program that is driven by input from a front-end FEPI application. It modifies the time stamp in the input message and returns the message to the front-end application.

IMS schedules this transaction when an input message is queued for it. It addresses the I/O PCB, DLI call function, and I/O area to build the parameter list for the GU call to retrieve the queued input message.

The time field of the input message is updated and the program then issues an ISRT call to place the message on the output queue. IMS then sends the output message to the front-end FEPI application.

Output messages from this program are all prefixed with a 5-byte function management header.

If any errors occur, the program ends with a nonzero return code.

        GETMAIN storage areas for reentrancy
        Address PCB
        Issue GU call to get input message
        Use TIME to obtain system time
        Update I/O area
        Issue ISRT call to send output message
        RETURN