Mitsubishi Q2ASCPU User Manual page 131

Error
Code Error Contents and Cause
(SD0)
• Since the standby system is in an
error or similar status in the
redundant system, the control system
cannot be switched to the standby
system.
• When an attempt was made to
6220
execute system switching, the control
system could not be switched to the
standby system due to a network
error of the control system.
(This can be detected from the control
system of the redundant system.)
Switching is disabled because of a bus
switching module error.
6221
(This can be detected from the control
system of the redundant system.)
The link module mounted on the
6230 standby system CPU module is the
remote master station.
Corrective Action
Check the standby system condition.
This is a bus switching module
hardware fault. (Contact your local
Mitsubishi representative.)
Check the system configuration status.
116
Corresponding
CPU
Q4AR
Q4AR