Mitsubishi Q12PRHCPU - Page 243

6
REDUNDANT SYSTEM NETWORKS
6.2 Redundant System Network Overview
6.2.2 MELSECNET/H Remote I/O network
6 - 20
1
OVERVIEW
2
SYSTEM CONFIGURATION
3
TRACKING CABLE
4
PROCEDURE FOR STARTING UP A REDUNDANT SYSTEM
5
REDUNDANT SYSTEM FUNCTIONS
6
REDUNDANT SYSTEM NETWORKS
7
PROGRAMMING CAUTIONS
8
TROUBLESHOOTING
(b) Output Status during System Switching
The remote I/O station's output is held during system switching.
[Example]
Diagram 6.15 shows the redundant system when the control system network
module detects a communication error, on the assumption that the control system
network module is the master station, and the standby system network module is
the sub-master station.
Diagram 6.15 Output Status during System Switching
Control system
Standby system
Tracking cable
Tracking cable
MELSECNET/H Remote I/O network
Remote I/O station
(station No. 3)
Remote I/O station
(station No. 2)
Control
system
Standby
system
MELSECNET/H Remote I/O network
Remote I/O station
(station No. 3)
Remote I/O station
(station No. 2)
Output is preserved
during system switching
Output is preserved
during system switching
3) Perform system switching
2) Send a system switching request
1) Communication
not possible
Stop
Master
station
Multiplexed Remote Master
Station (station No. 0)
Multiplexed Remote Sub-master
Station (station No. 1)
Multiplexed Remote Master
Station (station No. 0)
Multiplexed Remote Sub-master
Station (station No. 1)
Standby
System
Control
System