Mitsubishi MELSEC Q4ARCPU User Manual page 253

Error
Code Error Contents and Cause
(SD0)
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.
Any of the following errors was detected
in the backup mode.
• The standby system has not started
up in the redundant system.
• The standby system has developed a
6300 stop error in the redundant system.
• The CPU module in the debug mode
was connected to the operating
control system.
(This can be detected from the control
system of the redundant system.)
*1 The module whose first 5 digits of serial No. is 09012 or later.
Corrective Action
This is a bus switching module
hardware fault. (Contact your local
Mitsubishi representative.)
Check the system configuration status.
• Check whether the standby system is
on or not, and if it is not on, power it
on.
• Check whether the standby system
has been reset or not, and if it has
been reset, unreset it.
• Check whether the standby system
has developed a stop error or not,
and if it has developed the error,
remove the error factor and restart it.
• When the CPU module in the debug
mode was connected to the control
system operating in the backup
mode, make connection so that the
control system and standby system
are combined correctly.
240
Corresponding
CPU
Q4AR
QnPRH