Mitsubishi Electric MELSEC iQ-R Series User Manual page 120

Problem Check item
A station A2-1
cannot
perform data
A2-2
link.
A2-3
A2-4
A2-5
A2-6
A2-7
A2-9
A2-
10
4 TROUBLESHOOTING
118
4.5 Troubleshooting by Symptom
Description
Station number Is the station number correctly set
for the faulty station?
Transmission Is the transmission speed setting
speed correctly set for the faulty station?
Online status Is the CC-Link interface of the
(slave station) faulty station online?
Parameter • Are the module parameters,
setting such as number of stations and
station information, correctly
set?
• Does the master station have
no error?
• Module parameters in the
engineering tool.
Cable or other Are there no disconnection, short
parts circuit, incorrect wiring, poor
connection, and coexistence of
different cables? Do a
transmission distance, station-to-
station distance, transmission
cable, and FG terminal grounding
meet the specifications?
Are terminating resistors
connected?
Power supply (for Is the power on, and is the applied
communications) voltage within the specified
range?
Noise Is the transmission cable free from
noise?
Failure of a slave Do slave stations normally
station operate?
Standby master Is the standby master station
station controlling the data link?
Check method
Check the station number setting.
Check the transmission speed.
Check the status of the faulty station.
Check the module parameters of the
CPU module on the master station
using the engineering tool.
Check SW0068, SW0069, SW0070,
SW0071, SW0072, SW0074 to
SW0077, SW0098 to S009B, SW009C
to SW009F, SW0144 to SW0147.
Check if the SD LED and RD LED on
the faulty station are flashing.
When faulty stations occur sequentially
to one end on the transmission path,
check cables connected to faulty
stations close to the master station.
(Multiple stations)
Check if terminating resistors are
connected to the both ends in 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.
Check if the modules on the faulty
station are powered on.
Check if the applied voltage is within
the specified range.
Check if the transmission cable is
away from the power cable.
Check if the FG terminal is grounded
separated from the GND terminal of
the power system.
Reduce the transmission speed and
check if the frequency of occurrence of
noise is reduced.
Replace modules on the faulty station
and check if the station normally
operates.
Check if the standby master station is
not set as a station controlling the data
link by the CC-Link diagnostics of the
master station.
Action
Correct the station number setting.
Set the same transmission speed
as that set for other stations.
Set it online.
• Correct the module parameters.
• Format the CPU module
memory then write the module
parameters.
Correct the wiring.
Correct the wiring.
Connect terminating resistors to
the both ends in the CC-Link
system.
Power on the module.
Apply the voltage within the
specified range.
Keep the transmission cable away
from the power cable. (Keep a
distance of 100mm or more is
recommended)
Ground the terminals separately.
Take measures to reduce noise.
Reduce the transmission speed.
Repair or replace the module on
the faulty station.
Restart the system so that the
master station will control the data
link.