Design overview

The DFHSUWT module provides support for executing MVS WTO and WTOR SVCs.

SEND

supports Write To Operator (WTO):

• A single-line message up to 113 characters, or a multiline message consisting of a control line and up to nine lines of 69 characters
• Route code specification (route code list, which is made up of 1 through 28 numbers, each in the range 1 through 28)
• Descriptor code specification (descriptor code list, which is made up of 1 through 16 numbers, each in the range 1 through 16)

CONVERSE

supports Write To Operator With Reply (WTOR):

• A single-line message up to 121 characters
• Route code specification (route code list, which is made up of 1 through 28 numbers, each in the range 1 through 28)
• Descriptor code specification (descriptor code list, which is made up of 1 through 16 numbers, each in the range 1 through 16)
• A reply with maximum length of 119 characters

The DFHWTO macro may be used to send a message, normally to the system operator, when neither the CICS® message domain nor the old message program (DFHMGP) can be used. The message domain cannot be used during certain phases of initialization, because it requires a kernel stack environment. DFHMGP cannot be used during initialization, nor during any sort of abend or dump processing, because it uses task LIFO storage and may therefore invoke the storage control program.

The DFHWTO macro may also be used to terminate CICS abnormally or to request a reply from the operator.

Any WTO or WTOR macros that are issued by CICS might be intercepted by the console message handling facility described under Console message handling. This service optionally inserts the CICS region's applid into CICS messages before they are displayed on the console.