Master terminals in an XRF complex

In an XRF complex, each IMS must have its own master terminal, and it can have a secondary master terminal.

Typically, the secondary master terminal is a printer (output-only device type). System messages for the active and alternate subsystems go to their respective master terminals.

During a takeover, the console operators must know the status of the takeover on both systems. The operator at the alternate subsystem must know when I/O prevention in the failed active subsystem is complete; terminal switching of class-3 terminals and failed class-2 switch attempts must be handled.