Mitsubishi Electric MELSEC-Q Series User Manual page 284

(2) Problems due to disconnection of a slave station when the CC-Link system
has already operated
Problem Check item
B1-1 CPU module
Power supply (for
B1-2
communications)
Cable or other
B1-3
Data link
parts
cannot be
performed in
the entire
system.
B1-4 Noise
Failure of the
B1-5
master station
B1-6 Link stop
282
Description
Does the CPU module on the
master station have no error?
Isn't a voltage low?
Are there no disconnection,
short-circuit, and poor
connection?
Is the transmission cable free
from noise?
Do modules on the master
station normally operate?
Is Data link stop instruction
correctly executed?
Check method
Check the error code of the CPU
module.
Check if the module has been
identified.
Check power supplied to the
master station and all slave
stations.
Check if cables between the
master station and slave stations
are not disconnected.
Check if the transmission cable is
away from the power cable.
Check if the FG terminal is
grounded separately from the
GND terminal of the power
system.
Reduce the transmission speed
and check if the frequency of
occurrence of noise is reduced.
Replace the modules and check if
the station normally operates.
Check if Data link stop (SB0002)
is off.
Corrective action
Remove the error.
User's manual
for the CPU module
used (hardware
design, maintenance
and inspection)
Take corrective action
so that the CPU
module may identify
the master/local
module.
User's manual
for the CPU module
used (hardware
design, maintenance
and inspection)
Apply the voltage
within the specified
range.
Correct the wiring.
Keep the transmission
cable away from the
power cable. (Keep a
distance of 100mm or
more is
recommended.)
Ground the terminals
separately.
Take noise reduction
measures.
Reduce the
transmission speed.
Repair or replace the
module on the master
station.
Do not turn on Data
link stop (SB0002).
Do not write data to the
refresh source device
of Data link stop
(SB0002) from multiple
locations.
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