Mitsubishi Electric MELSEC-Q Series User Manual page 279

Problem Check item
A1-6 Link start
A1-7 CPU module
Data link
cannot be
performed in
the entire
system.
A1-8 Noise
Failure of the
A1-9
master station
Description
Is the CPU module set to
status other than RESET
when network parameters are
set?
Was the system started by the
automatic CC-Link startup?
Does the CPU module on the
master station have no error?
Isn't the sequence scan time
long in the synchronous
mode?
Is the transmission cable free
from noise?
Do modules on the master
station normally operate?
CHAPTER 11 TROUBLESHOOTING
Check method
Check if the switch on the CPU
module is not at the RESET
position.
Check if values are not set in the
intelligent function module switch
setting.
Check the error code of the CPU
module.
Check if the module has been
identified.
Check if the sequence scan time
is within the allowable 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 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.
Corrective action
Cancel the RESET
status.
Disable the intelligent
function module switch
11
setting of the
programming tool.
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)
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 noise reduction
measures.
Reduce the
transmission speed.
Repair or replace the
module on the master
station.
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