CMSG - message switching

Use CMSG to send messages from your terminal to one or more destinations.

The destination may be:
  • Another terminal
  • Another terminal, but only when a specified operator is signed on at that terminal
  • Another terminal, but only when the operator signed on at that terminal is in a specified class
  • Another operator (CICS locates the operator, if currently signed on, and sends the message to that operator's terminal)
  • All terminals
  • All terminals with operators signed on in specified classes
  • Any combination of these destinations.

You can specify that the message is to be sent at some future time. If the message cannot be sent, your terminal is notified.

In addition, standard routing lists can be provided using the terminal list table (TLT), which can include terminal and operator identifiers. Multiple routing lists can be specified at the time the message is entered, and individual destinations can be deleted from, or added to, the lists at this time.

CICS message switching is provided by a service program invoked by a user-defined transaction identifier that must be defined to CICS. This transaction identifier can be CMSG or any user-defined 4-character transaction identifier. CMSG is the transaction identifier assumed throughout this book.

You can extend message switching to include predefined messages and even complete message-switching transaction input formats.

The terminals from which message switching is initiated, and all terminals of message destinations, must support BMS.

Routed messages can be directed to a terminal, including the transaction terminal, that supports partitions. However, such messages reset the terminal to “base” state.