About messages
JES3 displays messages to the operator console in response to either system activity or in response to an operator command such as an *INQUIRY or *MODIFY request.
Messages are sent to the operator console (and also to the hardcopy medium) by both MVS™ and JES3, and by operators at other consoles.
Messages can be:
- Warnings about errors or dangerous conditions in the system
- Information about system activity or in response to your command or inquiry
Some messages ask you to respond:
- With a JES3 command
- With an MVS reply command (see Replying to MVS messages)
- By doing something away from the console (for example, mounting a tape or switching devices)
Messages issued by JES3 are documented in the z/OS JES3 Messages document.
The types of messages (MVS or JES3 or both) and the categories of messages received at each console are defined during initialization, depending on how each console is to function in the complex. Some of these characteristics can be changed by operator commands (see JES3 destination classes and MVS routing codes).