User`s manual

Error code list Troubleshooting
MELSEC System Q, Hardware 11 – 91
6220
CAN'T SWITCH
System switching cannot be executed due to
standby system error/ tracking cable error/
online module change in execution at separate
mode.
Causes for switching system at control system
are as follows:
– System switching by SP. CONTSW instruction
– System switching request from network mod-
ule
 Collateral information

Common Information: Reason(s) for system
switching
 Individual Information: Reason(s) for system
switching failure
 Diagnostic Timing
At switching execution
– Check the status of the standby system and
resolve the error.
– Complete the online module change.
ON ON No error QnPRH
6300
STANDBY SYS. DOWN
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 stop
error in the redundant system.
– The CPU module in the debug mode was con-
nected to the operating control system.
(This can be detected from the control system of
the redundant system.)
 Collateral information

Common Information: —
 Individual Information: —
 Diagnostic Timing
Always
– 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 devel-
oped a stop error or not, and if it has devel-
oped the error, remove the error factor and
restart it.
– When the CPU module in the debug mode
was connected to the control system operat-
ing in the backup mode, make connection so
that the control system and standby system
are combined correctly.
ON ON Continue QnPRH
6310
CONTROL SYS. DOWN
Any of the following errors was detected in the
backup mode.
– The control system has not started up in the
redundant system.
– The control system has developed a stop
error in the redundant system.
– The CPU module in the debug mode was con-
nected to the operating standby system.
– The error occurred at a startup since the
redundant system startup procedure was not
followed.
(This can be detected from the standby system
of the redundant system.)
 Collateral information

Common Information: —
 Individual Information: —
 Diagnostic Timing
Always
– The standby system exists but the control
system does not exist.
– Check whether the system other than the
standby system is on or not, and if it is not
on, power it on.
– Check whether the system other than the
standby system has been reset or not, and if it
is has been reset, unreset it.
– Check whether the system other than the
standby system has developed a stop error or
not, and if has developed the error, remove
the error factor, set the control system and
standby system to the same operating status,
and restart.
– When the CPU module in the debug mode
was connected to the control system operat-
ing in the backup mode, make connection so
that the control system and control system
are combined correctly.
– Confirm the redundant system startup proce-
dure, and execute a startup again.
OFF Flicker Stop QnPRH
6311 CONTROL SYS. DOWN
– As consistency check data have not been
transmitted from the control system in a
redundant system, the other system cannot
start as a standby system.
– The error occurred at a startup since the
redundant system startup procedure was not
followed.
(This can be detected from the standby system
of the redundant system.)
 Collateral information

Common Information: —
 Individual Information: —
 Diagnostic Timing
At power ON/At reset
– Replace the tracking cable.
If the same error still occurs, this indicates
the CPU module is faulty.
Contact your local Mitsubishi representative.
– Confirm the redundant system startup proce-
dure, and execute a startup again.
OFF Flicker Stop QnPRH
6312
Error
code
Error contents and cause Corrective action
LED status
CPU
status
Corre-
sponding
CPU
RUN ERR.
Tab. 11-8: Error code list (6000 to 6999) for PLC CPUs of MELSEC System Q