Transaction Definitions

Every transaction id that users type - ORD1, INQ2, PAY3 - needs a TRANSACTION definition. It tells CICS which program to start, how much working storage the task gets, and the rules the task runs under.

What a transaction definition contains

• TRANSACTION - the 1 to 4 character id users type, for example ORD1.
• PROGRAM - the first program CICS links to when the transaction starts. That program must itself be defined.
• TWASIZE - size in bytes of the transaction work area (TWA), used to pass data between programs in the same task.
• STATUS - ENABLED lets the transaction run; DISABLED blocks it with a message.
• PROFILE - message and option profile, usually DFHCICSA. It controls things like upper/lower case handling and journaling.
• TRANCLASS - groups transactions so CICS can limit how many run at the same time.
• TASKDATAKEY - CICS or USER key for task storage, a security boundary for storage protection.

Important attributes explained

• TWASIZE must be big enough for the largest COMMAREA the transaction chain passes. Too small gives storage overlays and ASRA abends.
• PROGRAM points at a PROGRAM definition, not directly at the load module. If the program definition is missing you get PGMIDERR.
• STATUS(DISABLED) is the safe way to take one transaction out of service without touching the program.
• ISOLATE(YES) gives the task its own storage protection; use it for untrusted or new code.
• RESSEC and CMDSEC switch on resource and command security checking for the transaction.
• TCLASS is the old name still seen in shops; TRANCLASS is the modern replacement.

Defining a transaction with CEDA

• Type the DEFINE command on a CICS terminal, fill the overtype screen, then press Enter. PF3 saves it into the group.
• Install the group before anyone can use the new transaction id.

Example - define transaction ORD1 in group ORDGRP: