The IMS node sends a bit stream to IMS, which schedules one of its programs to process the message. The program generates a message, which IMS sends back to the IMS node, as illustrated in the following diagram.
The bit stream contains the routing information that IMS needs so that it can schedule a program to receive that bit stream. The structure of the bit stream varies depending on whether it is a request or response bit stream. The structure of the different bit streams are described in the following sections.
Request bit stream
The structure of the
request bit stream is illustrated by the following diagram.
- LLZZ is a four-byte field. The first two bytes indicate the length of the bit stream, and the other two bytes are reserved for use by IMS.
- The transaction code can contain up to eight characters. If the code contains less than eight characters, the transaction code must be delimited by a space. When the transaction code is less than eight bytes, IMS reads only the transaction code and one space. The response segments do not need to have the transaction name, but an IMS program can add it.
- The rest of the bit stream comprises the data that the IMS program needs.
Response bit stream
The structure of the response bit stream is illustrated by the following diagram.
Commands
You can also use bit streams to run commands. The structure of the response bit stream is illustrated by the following diagram.
For more information about IMS concepts,
see the following topics:
Last updated Friday, 21 July 2017