CICS-to-IMS applications: DTP

This section describes application programming for CICS® -to- IMS distributed transaction processing (DTP).

CICS commands for CICS-to-IMS sessions
These are the commands that can be used to acquire and use CICS-to-IMS sessions.
Considerations for the front-end transaction
Except in the special case of the receiving transaction in SEND and RECEIVE asynchronous processing, the CICS transaction is always the front-end transaction in CICS-to-IMS DTP.
Attaching the remote transaction
When a session has been acquired, the next step is to cause the remote IMS process to be initiated.
Considerations for the back-end transaction
A CICS transaction can be the back-end transaction in CICS-to-IMS communication only in the special case of SEND and RECEIVE asynchronous processing.
The conversation
The conversation between the front-end and the back-end transactions is held using the usual SEND, RECEIVE, and CONVERSE commands.
Freeing the session
You must free the session after issuing a SEND LAST command, or when the EIBFREE field has been set.
The EXEC interface block (EIB)
The EIB fields that are of particular significance in ISC applications are described.
Command sequences for CICS-to-IMS sessions
The command sequences that you use to communicate between the front-end and the back-end transactions are governed both by the requirements of your application and by a set of high-level protocols designed to ensure that commands are not issued in inappropriate circumstances.
State diagrams
You can use the state diagrams to construct valid command sequences. Each diagram relates to one specific state and shows the commands that you might issue, and the tests to make, after you issue the command.

Parent topic: CICS-to-IMS applications

Related concepts

CICS-to-IMS applications: asynchronous processing
Designing CICS-to-IMS ISC applications

Related information

Defining CICS-to-IMS LUTYPE6.1 links