Differences between CICS, IMS, and MVS

TDINFRPC TDSTATUS

The action taken when the communication state (COMM_STATE) is TDS_RESET can differ between CICS, MVS and the IMS TM implicit API:

• Under CICS, MVS, and the IMS TM explicit API, the transaction exits as soon as possible.

• Under the IMS TM implicit API, the transaction can call TDGETREQ to accept another client request or it can exit.

TDINIT

The first argument differs between CICS and IMS TM:

• Under CICS, the communications I/O block, passed as the first parameter in TDINIT, is the EIB (DFHEIBLK).

• Under IMS TM, the first TDINIT parameter is I/O PCB (IO_PCB).

• Under MVS, a null pointer should be used.

TDSETPT

Used with IMS TM only, to indicate the type of IMS TM transaction.

TDSNDDON

Value of CONN_OPTIONS in CICS, MVS, and the IMS TM explicit API can be set to TDS_ENDREPLY in long-running transactions. TDS_ENDREPLY cannot be used under the IMS TM implicit API. To learn how to simulate long-running transactions in the implicit API, see “Long-running transactions”.

TDINFACT TDSETACT

Accounting records are written to different logs under CICS, IMS TM and MVS:

• Under CICS, accounting functions use VSAM files as log files. The default file name is SYTACCT1.

• Under IMS TM, accounting functions use the IMS TM log.

• Under MVS, the records are written to a sequential file. The DDNAME of this file is specified as a parameter in TDCUSTOM (MVSDDNAME).

TDINFLOG TDINFSPT TDLSTLSPT TDSETLOG TDSETSPT TDWRTLOG

Trace records are written to different logs under CICS, IMS TM and MVS:

• Under CICS, tracing functions use VSAM files as log files. The default file name is SYTDLOG1.

• Under IMS TM, tracing functions use the IMS TM log.

• Under MVS, the records are written to a sequential file. The DDNAME of this file is specified as a parameter in TDCUSTOM (MVSDDNAME).