Mitsubishi Electric L26CPU-BT User Manual page 350

Description
Check item
of problem
A2-5 Cables
Power supply
Some station(s)
A2-6 (for
cannot be linked.
communication)
A2-7 Noise
Device station
A2-9
failure
Standby master
A2-10
station
348
Check contents
Is there any disconnection,
short-circuit, incorrect
wiring, faulty connection, or
status out of specifications
(transmission distance,
distance between stations,
transmission cable,
coexistence of different
cables or FG connection)?
Are the terminating
resistors connected?
Is the power off or out of
the range of use?
Is there any noise on the
transmission cable?
Is the device station failed?
Is the standby master
station controlling the data
link?
Check procedure
Check if the SD LED and RD
LED are flashing 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 if the terminating
resistors are connected to the
both ends of the CC-Link
system.
Check if a station with built-in
terminating resistor is
connected other than at both
ends in the CC-Link system.
Is the power on at the faulty
station?
Is the supplied power within the
specified range?
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.
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.
Corrective action
Connect the cable properly.
Connect the cable properly.
Connect the terminating
resistors to the both ends
of the CC-Link system.
Turn the power supply on.
Set the supplied voltage to
within the specified range.
Wire the transmission
cable and power wiring as
separated as possible.
(recommended to keep a
distance of more than
100mm)
Set FG and the power
system GND apart.
Take measures against
noise.
Reduce the transmission
speed.
Fix or replace the failed
device station.
Reboot the system and set
the control by the master
station.