State Transition Of A Redundant System - Mitsubishi Electric MELSEC iQ-R Series User Manual

11.7

State Transition of a Redundant System

The following figure shows the state transition of a redundant system after start-up based on the operation mode change and
system switching.
Power on the system B. (2)
Backup mode
System A: Off
System B: Control system
Power off the system A.
Separate mode
System A: Off
System B: Standby system
System A: Off
System B: Control system
(1) When both systems are powered off, both systems transition to the power-off state regardless of the operation mode or system type.
(2) A system that is powered on starts up as the control system. ( Page 163 When only one system is started up)
Both systems: Powered off (1)
System A: Off
System B: Off
Power off the
system A.
System A: Control system
(System switching)
System B: Standby system
Power on the system A.
System A: Standby system
System B: Control system
Operation mode change
Power off the
System A: Control system
system A.
Power on the
System B: Standby system
system A.
Power off the
System A: Standby system
system A.
System B: Control system
Power on the
system A.
Power on the both systems.
Power off the
system B.
Power on the
system B.
System switching
Operation mode change
Power off the
system B.
Power on the
system B.
System switching
Power off the
system B.
Power on the
system B.
11 BASIC CONCEPT OF REDUNDANT SYSTEM
11.7 State Transition of a Redundant System
Power on the system A. (2)
System A: Control system
System B: Off
Power off the system B.
(System switching)
System A: Control system
System B: Off
System A: Standby system
System B: Off
175
11