SMC Networks EX120-SDN1-X2 Operation Manual page 33

Fault No.3
Problem Possible cause
MAC ID
duplication error
SI unit
BUS OFF error
MOD/NET LED
is ON Red
Failure of the
communication
device
Fault No.4
Problem Possible cause
SI unit
I/O connection
MOD/NET LED
timeout
flashes Red
Investigation method
Check that there is no MAC ID duplication
between the master and slave.
Check that the length of the communication
cable is suitable for the communication speed,
check for terminators at both ends, and check
that the special cable for DeviceNet
Check that there is no equipment or high
voltage cables which generates noise around
the communication and power supply cables.
TM
Check the DeviceNet cable connections and
check for broken wires.
Confirm that repeated bending stresses or
pulling forces are not applied to the cable which
may cause broken wire.
Confirm that the SI unit communication speed
setting and the communication speed settings
of the master and slave are the same.
-
Investigation method
Check that the length of the communication
cable is suitable for the communication speed,
check for terminators at both ends, and check
that the special cable for DeviceNet
Check that there is no equipment or high
voltage cables which generates noise around
the communication and power supply cables.
TM
Check the DeviceNet cable connections and
check for broken wires.
Confirm that repeated bending stresses or
pulling forces are not applied to the cable which
may cause broken wire.
Confirm that power is supplied to the master
station.
-32-
Countermeasures
Correct the MAC ID settings.
Correct the wiring and
settings.
TM
is used.
Separate the communication
and power supply cables
away from noise sources.
Correct the connection of the
TM
DeviceNet
Correct the communication
speed settings.
Replace the SI unit.
Countermeasures
Correct the wiring and
settings.
TM
is used.
Separate the communication
and power supply cables
away from noise sources.
Correct the connection of the
TM
DeviceNet
Supply power to the master
station correctly.
No.EX##-OME0015-C
cable.
cable.