Mitsubishi LJ61BT11 User Manual page 333

Description of problem
A4-1
A4-2
Some station(s)
cannot be linked
A4-3
occasionally.
A4-4
A4-5
A4-6
15 - 12
Check item
Is there any disconnection, short-
circuit, incorrect wiring, faulty
connection, or status out of
specifications (transmission
Cables
distance, distance between
stations, transmission cable,
coexistence of different cables or
FG connection)?
Power supply (for Is the power off or out of the
communication) range of use?
Is there any noise on the
Noise
transmission cable?
Startup Is the startup sequence correct?
Slave station failure Is the slave station failed?
Standby master Is the standby master station
station controlling the data link?
Check contents
Check the cable at the faulty
station.
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. (multiple
stations)
Check the power supply at the
faulty station.
Check if the transmission cable
and power wiring are separated
enough.
Check if the FG is separated from
the power system GND.
Reduce the transmission speed
and then check the occurrence
frequency.
Check by changing the startup
sequence of the failure station.
Replace the failed station and
check the operation.
Check if the master station
switching status is in the standby
master station, with the master
station CC-Link diagnostics.
15 TROUBLESHOOTING
Check procedure
Connect the corresponding cable
properly.
Set the supplied voltage to within
the specified range.
Wire the transmission cable and
power wiring as separated as
possible.
Set FG and the power system
GND apart.
Take measures against noise.
Reduce the transmission speed.
Startup with the procedure
described in the manual of the
corresponding station.
Fix or replace the failed slave
station.
Reboot the system and set the
control by the master station.
Corrective action
15 - 12