Mitsubishi Electric MELSEC SW1DNC-CCIEF-B User Manual page 182

<Figure 2 When system switching occurs due to standby system error>
CC-Link IE Field Network
Connection to the
control system
Personal computer
(CC-Link IE Field
Network board)
CC-Link IE Field Network
Connection to the
control system
Personal computer
(CC-Link IE Field
Network board)
• Path switching is not executed when a communication to the Redundant CPU specified at Logical station
No. is faulty at communication start
When a communication is faulty, refer to the following and clear the communication disturbance.
(Page 179 Checking method of path switching occurrence, Page 179 Access examples of path
switching)
• If other station access (including the programmable controller CPU other than the Redundant CPU) is made
to 257 or more stations simultaneously, communication path may not be automatically switched.
*1 First communication after execution of the mdOpen function in the MELSEC data link library (communications using the mdReceiveEx,
mdSendEx, mdDevRstEx, mdDevSetEx, mdRandREx, mdRandWEx, mdReceive, mdSend, mdControl, mdDevRst, mdDevSet,
mdRandR, mdRandW or mdTypeRead function).
APPX
180
Appendix 1 Precautions for Accessing Redundant CPU System
CC-Link IE Field Network module
MELSECNET/H module
MELSECNET/H
Control system
CC-Link IE Field Network module
MELSECNET/H module
MELSECNET/H
Control system
*1
(A communication error occurs.)
Standby system
Standby system
error
Tracking cable
Standby system
Tracking cable