IMS Special Features (SAP Library - SAP Communication: CPI-C Programming (BC-CST-GW))

IMS Special Features

The individual parameters required for LU6.2 communication are listed in the description of the IBM LU6.1 adapter for LU6.2 applications.

SAP is subject to all the restrictions of the LU6.1 adapter for LU6.2 applications.

For communication with an R/2 System in IMS environment, the following parameters are particularly important:

Active connection:

The active establishment of a connection from the SAP system is only possible to the partner program IMSASYNC in asynchronous mode.

Here, asynchronous means that a RECEIVE statement is not permitted, but the conversation must be acknowledged using CONFIRMED ( Status = CM_CONFIRM_DEALLOC_RECEIVED).

An IMSASYNC program should always be defined to receive and acknowledge data to be processed asynchronously from the IMS Message Queue.

Remotely attachable ABAP program:

The SAP service transaction xxxX1SA is conversational.
Several RECEIVE calls in sequence are not permitted. There must be at least one SEND call between two RECEIVE calls. The program status is displayed in the status field.
The length of a transferred message must always be larger than zero.
If several SEND statements are sent in succession, or very long messages are sent, segmentation will occur in the IMS receiver system.

Only the first segment of a message is processed (up to 5.0C), so that data can be cut off.

From R/2 Release 5.0D, the individual segments are concatenated and passed to the SAP application as a complete message.

An external DEALLOCATE or a termination of the partner program are not passed on to the SAP system. For this reason, DEALLOCATE must always be called in the ABAP program in the IMS system.
External security systems are not supported directly.

Alternatively, you can call the command /SIGN. Use SEND to send the USERID/PWD to IMS. Use RECEIVE to get the corresponding IMS message: DFSxxx....