To extend the number of consoles on MVS™ systems or to allow applications and programs to access MVS messages and send commands, an installation can use extended MCS consoles. The use of these consoles can help alleviate the constraint of the MCS console limit. Moving to an extended MCS console base from a subsystem-allocatable console base will allow for easier expansion in a sysplex.
You can define a TSO/E user to operate an extended MCS console from a TSO/E terminal. The user issues the TSO/E CONSOLE command to activate the extended MCS console.
An installation can also write an application program to act as an extended MCS console. An authorized program issues the MVS authorized macro MCSOPER to activate and control the extended MCS console and uses other MVS macros and services to receive messages and send commands.
In an application program, you can define your own message presentation service, or handle messages and commands that can help automate certain tasks.
For example, you might want to run a program that activates an extended MCS console to control printer operations for a system or sysplex. Because you can direct messages and commands from any system in a sysplex to a specific extended MCS console, you can design programs to control certain automation functions for the entire sysplex.
Both JES2 and JES3 installations can use extended MCS consoles.