Mitsubishi L26CPU-BT, User Manual

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15 TROUBLESHOOTING
(2) Problems on slave station disconnection (when the CC-Link system
has been normally operated)
Description of problem Check item Check contents Check procedure Corrective action
Check the error code of the
programmable controller CPU.
Correct the error code of the
programmable controller CPU.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
B1-1
Programmable
controller CPU check
Does any error occur at the
programmable controller CPU of
the master station?
Check if the module can be
recognized.
Recognize the L series
master/local module properly.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
B1-2
Power supply (for
communication)
Is any voltage drop occurring?
Check the power supply of the
master station and all slave
stations.
Set the supplied voltage to within
the specified range.
B1-3 Cables
Is there any disconnection, short-
circuit or faulty connection?
Check if the cable between the
master station and slave station is
connected properly.
Connect the cable properly.
Check if the transmission cable
and power wiring are separated
enough.
Wire the transmission cable and
power wiring as separated as
possible. (recommended to keep
a distance of more than 100mm)
Check if the FG is separated from
the power system GND. Set FG and the power system
GND apart. B1-4 Noise
Is there any noise on the
transmission cable?
Reduce the transmission speed
and then check the occurrence
frequency.
Take measures against noise.
Reduce the transmission speed.
B1-5 Master station failure Is the master station failed?
Check if the system operates
properly after replacing the
master station.
Fix or replace the master station.
Unable to link the
entire system.
B1-6 Link stop
Is the data link stop instruction
being executed properly? Check if the data link stop
(SB0002) is turned on.
Disable the data link stop
(SB0002).
Do not use devices which read
SB0002 simultaneously.
B2-1
Power supply (for
communication)
Is any voltage drop occurring?
Check the power supply at the
faulty station. Set the supplied voltage to within
the specified range.
Check the connection cable at the
faulty station.
B2-2 Cables
Is there any cable/connector
disconnected or out of
specifications?
Check the cable of the closest
faulty station from the master
station, when multiple stations are
sequentially faulty to the terminal
of the transmission path.
Connect the corresponding cable
properly.
Check if the transmission cable
and power wiring are separated
enough.
Wire the transmission cable and
power wiring as separated as
possible.
(recommended to keep a
distance of more than 100mm)
Check if the FG is separated from
the power system GND. Set FG and the power system
GND apart.
B2-3 Noise
Is there any noise on the
transmission cable?
Reduce the transmission speed
and then check the occurrence
frequency. Execute the protection against
noise.
Reduce the transmission speed.
A station cannot be
linked occasionally.
B2-4 Slave station failure Is the slave station failed?
Replace the failed station and
check the operation. Fix or replace the failed slave
station.