Mitsubishi Electric SW0DNC-MNETH-B User Manual page 196

APPENDIX
App.
POINT
To judge which system in the Redundant CPU system is being accessed by MELSECNET/H
board, create a program to monitor the following special relays.
(1) When checking which system is being accessed, System A or System B
SM1511
SM1512
(2) When checking the operation system status
SM1515
SM1516
App - 2
(2) Operation at occurrence of system switching
When system switching occurs during access to the Redundant CPU, access to
the Redundant CPU set for the Logical Sta. No. is continued.
(Example) When the following Logical Sta. No.66 was specified for access
Logical Sta. No.66
Before system switching
After system switching
 Identifies system A/system B of a redundant system.
System A
 Remains ON/OFF even if the tracking cable is disconnected while the redundant system
identification
is running.
flag
System B
SM1511
identification
SM1512
flag
 Indicates the CPU module operation status
 Remains ON/OFF even if the tracking cable is disconnected while the redundant system
is running.
Control/
Standby
system
status
SM1515
SM1516
Network No.:
Sta. No.:
Multiple PLC specify:
Redundant PLC specify: Control system
Personal computer
(MELSECNET/H board)
Control system
Station No. 1
Personal computer
(MELSECNET/H board)
Control system
Standby system
Station No. 1
At the time of TRK.CABLE ERR.(Error code:
System A System B
6120) occurrence (System not determined.)
ON OFF
OFF ON
Control Standby At the time of TRK.CABLE ERR.(Error code:
system system 6120) occurrence (System not determined.)
ON OFF
OFF ON
1
1
No specification
Station No. 3
MELSECNET/H
(Network No.1)
Standby system
Tracking cable
Station No. 2
Station No. 3
MELSECNET/H
(Network No.1)
Standby system
Control system
Tracking cable
Station No. 2
OFF
OFF
OFF
OFF
MELSEC
App - 2