When A Slave Station Is Disconnected - Mitsubishi Electric MELSEC iQ-R Series User Manual

When a slave station is disconnected

When a system is newly configured or the system is changed
Problem Check item
Data link A1-1 Station number
cannot be
performed in
A1-2 Transmission
the entire
speed
system.
A1-3 Mode
A1-4 Parameter
setting
A1-5 Cable or other
parts
A1-6 CPU module
A1-7 Noise
A1-8 Failure of the
master station
Description
Is the station number correctly set
for the faulty station?
Are the transmission speed values
set within the range, and same
between the master station and
slave stations?
Is the online mode set to the
master station?
• Are the module parameters,
such as number of stations and
station information, correctly
set?
• Does the master station have
no error?
• Module parameters in the
engineering tool.
Are there no disconnection, short
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?
Does the CPU module on the
master station have no error?
Is the sequence scan long?
(Synchronous mode)
Is the transmission cable free from
noise?
Do modules on the master station
normally operate?
Check method
Check the station number setting.
Check the transmission speed settings
of all stations.
Check the mode setting of the master
station.
Check the parameters of the CPU
module on the master station using the
engineering tool.
Check 'Station number of own station'
(SW0061) and 'Mode setting status'
(SW0060).
Check SW0068, SW0069, SW0070,
SW0071, SW0072, SW0074 to
SW0077, SW0098 to S009B, SW009C
to SW009F, SW0144 to SW0147.
Check if cables between the master
station and slave stations are not
disconnected.
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 the error code of the CPU
module.
Check if the module has been
identified.
Check if the sequence scan time is
within the range.
10Mbps: 50ms
5Mbps: 50ms
2.5Mbps: 100ms
625kbps: 400ms
156kbps: 800ms
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 the modules and check if the
station normally operates.
4.5 Troubleshooting by Symptom
Action
Correct the station number setting.
Correct the transmission speed
setting.
Set the online mode.
• Correct the module parameters.
• Format the CPU module
memory then write the module
parameters.
Correct the wiring.
Connect terminating resistors to
the both ends in the CC-Link
system.
Remove the CPU module error.
(MELSEC iQ-R CPU Module
User's Manual (Application))
Take action so that the CPU
module may identify the master/
local module. (MELSEC iQ-R
CPU Module User's Manual
(Application))
Set the asynchronous mode or
reduce the transmission speed.
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 master station.
4 TROUBLESHOOTING
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