Mitsubishi Electric L26CPU-BT User Manual page 351

Description
Check item
of problem
A3-1 Cables
Parameter
A3-2
setting
Power supply
A3-3 (for
communication)
Unable to link
the entire
system
occasionally.
A3-4 Noise
Master station
A3-5
failure
A3-6 Link stop
A4-1 Cables
Some station(s)
cannot be linked
occasionally.
Power supply
A4-2 (for
communication)
Check contents
Is there any
Check the cable between the
cable/connector
master station and device
disconnected or out of
station.
specifications?
Does the sequence scan time
exceed the tolerance?
Is not the sequence scan 10Mbps: 50ms
too long? (synchronous 5Mbps: 50ms
mode) 2.5Mbps: 100ms
625kbps: 400ms
156kbps: 800ms
Check the power supply of the
Is the power off or out of
master station and all device
the range of use?
stations.
Check if the transmission cable
and power wiring are separated
enough.
Is there any noise on the
transmission cable? Check if the FG is separated
from the power system GND.
Reduce the transmission
speed and then check the
occurrence frequency.
Check if the system operates
Is the master station failed? properly after replacing the
master station.
Is the data link stop
Check if the data link stop
instruction being executed
(SB0002) is turned on.
properly?
Is there any disconnection, Check the cable at the faulty
short-circuit, incorrect station.
wiring, faulty connection, or
Check the cable of the closest
status out of specifications
faulty station from the master
(transmission distance,
station, when multiple stations
distance between stations,
are sequentially faulty to the
transmission cable,
terminal of the transmission
coexistence of different
path. (multiple stations)
cables or FG connection)?
Check if the terminating
resistors are connected to the
both ends of the CC-Link
system.
Are the terminating
resistors connected?
Check if a station with built-in
terminating resistor is
connected other than at both
ends in the CC-Link system.
Is the power off or out of Check the power supply at the
the range of use? faulty station.
CHAPTER 15 TROUBLESHOOTING
Check procedure Corrective action
Connect the corresponding
cable properly.
Switch to the
asynchronous mode, or
reduce the transmission
speed.
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 master
station.
Disable the data link stop
(SB0002).
Do not use devices which
read SB002
simultaneously.
Connect the corresponding
cable properly.
Connect the terminating
resistors to the both ends
of the CC-Link system.
Set the supplied voltage to
within the specified range.
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