State Transition Of The Redundant System - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

26.8

State Transition of the Redundant System

The following figure shows the state transition due to the operation mode change and system switching for the redundant
system after start-up.
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 enter the power-off state regardless of the operation mode or system type.
(2) When a system that has been powered is started as the control system. ( Page 411 When starting up one system first)
26 BASIC CONCEPT
420
26.8 State Transition of the Redundant System
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. System A: Control system
Power on the
System B: Standby system
system A.
Power off the
System A: Standby system
system A.
Power on the System B: Control system
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.
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