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MELSEC-Q
14 SYSTEM CONFIGURATION OF MULTIPLE PLC SYSTEM
14.2.7 Resetting the multiple PLC system
It is possible to reset the entire multiple PLC system by resetting the PLC No.1.
The CPU modules for PLC No.2 to No.4, I/O modules and intelligent function modules
will be reset when the PLC No.1 is reset.
If a stop error occurs for any of the PLCs on the multiple PLC system, either reset the
PLC No.1 or restart the sequencer (power supply ON OFF ON) after the problem
has been recovered.
(Recovery is not allowed by resetting the CPU modules for PLC No.2 to No.4 for which
stop errors have occurred.)
0 1 2 3 4
Po
we
r su
p
p
ly
5 6 7
PL
C No
.1
PL
C No
.2
The entire multiple PLC system can be reset.
Reset is not allowed with the multiple PLC system.
If a reset is attempted all PLCs on the multiple
PLC system will assume the "MULTIPLE PLC DOWN" status.
PL
C No
.3
PL
C No
.4
QCP
U
QCP
U
QCP
U
QCP
U
POINT
(1) It is not possible to reset the CPU modules for PLC No.2 to No.4 individually in
the multiple PLC system. If an attempt to reset any of the CPU modules for
PLC No.2 to No.4 during operation of the multiple PLC system, a "MULTIPLE
PLC DOWN (error code: 7000)" error will occur for the other PLCs, and the
entire multiple PLC system will be halted. However, depending on the timing in
which the CPU modules have been reset, there are cases where errors other
than the "MULTIPLE PLC DOWN" error will halt the other PLCs.
(2) A "MULTIPLE PLC DOWN (error code: 7000)" error will occur regardless of the
operation mode set at the "Multiple PLC settings" screen within the (PLC)
Parameter dialog box. (stop/continue all other PLCs on the CPU modules for
PLC No.2 to No.4 error) when the CPU modules for PLC No.2 to No.4 are reset
(See Section 14.2.8 for details on the multiple PLC setting operation modes.)