Mitsubishi QJ71LP21 User Manual

8 TROUBLESHOOTING
MELSEC-Q
8 - 144 8 - 144
*1 : Characters in parentheses ( ) indicate the special register numbers where individual information is being
stored.
Error
Code
(SD0)
*1
Error Contents and Cause Corrective Action
Corresponding
CPU
6220
• 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
execute system switching, the
control system could not be
switched to the standby system due
to a network error of the control
system.
Check the standby system condition. Q4AR
System switching cannot be executed
as the standby system or tracking
cable is faulty in a redundant system.
The following shows the reasons for
system switching on the control
system.
• System switching by SP. CONTSW
instruction
• System switching request from
network module
Check the status of the standby
system and resolve the error.
QnPRH
6221
Switching is disabled because of a bus
switching module error.
This is a bus switching module
hardware fault. (Contact your local
Mitsubishi representative.)
Q4AR
6230
The link module mounted on the
standby type CPU is the remote
master station.
Check the system configuration status.

Mitsubishi QJ71LP21 Specifications

General

Brand	Mitsubishi
Model	QJ71LP21
Category	Controller
Language	English