Mitsubishi LJ61BT11 User Manual page 331

Description of problem
A1-7
Unable to link the
entire system.
A1-8
A1-9
A2-1
A2-2
A2-3
Some station(s)
cannot be linked.
A2-4
15 - 10
Check item
Does any error occur at the
programmable controller CPU of
the master station?
Programmable
controller CPU check
Is not the sequence scan too
long? (synchronous mode)
Is there any noise on the
Noise
transmission cable?
Master station failure Is the master station failed?
Is the station number setting at
Station No.
the faulty station correct?
Is the transmission speed at the
Transmission speed
faulty station correct?
Online status (slave Is the CC-Link interface at the
station) faulty station in the online status?
• Are the network parameters
(such as unit number or
station information) correct?
• Is some error occurring at the
master station?
Parameter setting
• Network parameter of the GX
Works2
Is the setting correct? (Automatic
CC-Link startup)
Check contents
Check the error code of the
programmable controller CPU.
Check if the module can be
recognized.
Does the sequence scan time
exceed the tolerance?
10 Mbps : 50 ms
5 Mbps : 50 ms
2.5 Mbps: 100 ms
625 kbps: 400 ms
156 kbps: 800 ms
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.
Check if the system operates
properly after replacing the
master station.
Check the station number setting
at the corresponding station.
Check the setting of the
transmission speed at the
corresponding station.
Check the status of the faulty
station.
Check the contents of the
network parameters for the
programmable controller CPU of
the master station.
Check SW0068, SW0069,
SW0070, SW0071, SW0072,
SW0074 to SW0077, SW0098 to
SW009B, SW009C to SW009F
and SW0144 to SW0147.
Check if any value is set to the
intelligent function module switch
setting.
15 TROUBLESHOOTING
Check procedure
Correct the error code of the
programmable controller CPU.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
Recognize the L series
master/local module properly.
Refer to MELSEC-L CPU Module
User's Manual (Hardware Design,
Maintenance and Inspection)
Switch to the asynchronous
mode, or reduce the transmission
speed.
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.
Execute the protection against
noise.
Reduce the transmission speed.
Fix or replace the master station.
Set the station number properly.
Correct the transmission speed.
Set the online status.
Set the network parameter
properly.
Execute the memory format of
the programmable controller CPU
and then write the network
parameter.
Disable the intelligent function
module switch settings in GX
Works2.
Corrective action
(To the next page)
15 - 10