Mitsubishi QJ71BR11 User Manual

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MELSEC-Q
7 APPLICATION FUNCTIONS
7.11.3 System switching request function of control system
The control system includes the system switching request function, i.e., the network
module mounted in the control system issues the system switching request to the
QnPRHCPU when it detects the data link error such as link cable disconnection or
communication error. This function enables the standby system to continue the control
even when the network module of the control system goes down.
Multiplexed remote master station
Control system
Power
supply
QnPRHCPU
QJ71
LP21
Link cable
Multiplexed remote sub-master station
Standby system
System switching due to network error
Tracking cable
Error notice
A disconnection has occurred
Power
supply
QnPRHCPU
QJ71
LP21
Multiplexed remote master station
(sub-master operation)
Standby system
Power
supply
QnPRHCPU QJ71
LP21
Multiplexed remote sub-master station
(master operation)
Control system
Power
supply
QnPRHCPU QJ71
LP21
System B
System BSystem A
However, if the QnPRHCPU of the control system cannot perform system switching
due to the standby system error, only the master operation of the network module
shifts to the network module of the standby system (multiplexed remote sub-master
station).
In this case, since the QnPRHCPU of the standby system cannot process the
sequence program, the CPU controls the network only. (Various modules mounted in
remote I/O stations cannot be controlled.)
Multiplexed remote master station
(sub-master operation)
Control system
Power
supply
QnPRHCPU
QJ71
LP21
Multiplexed remote sub-master station
(master operation)
Standby system
Power
supply
QnPRHCPU QJ71
LP21
System BSystem A
Under an error
REMARK
For the details of system switching, refer to QnPRHCPU User's Manual (Redundant
System).

Mitsubishi QJ71BR11 Specifications

General

Brand	Mitsubishi
Model	QJ71BR11
Category	Controller
Language	English