APPC/IMS application programs

APPC/IMS has three different types of application programs: standard, modified, and CPI Communications driven.

The application programs are defined as:

Standard: No explicit use of CPI Communications facilities.
Modified: Uses the I/O PCB to communicate with the original input terminal. Uses CPI Communications calls to allocate new conversations and to send and receive data.
CPI Communications driven: Uses CPI Communications calls to receive the incoming message and to send a reply on the same conversation. Uses the DL/I APSB call to allocate a PSB to access IMS databases and alternate PCBs.

You can schedule your standard and modified application programs locally and remotely using MSC. The logic for local application programs differs from the logic for remote application programs. In the following topics, the differences are described.