SMC Networks EX12 SCS Series Operation Manual page 26

○Faults and countermeasures
No. Problem Possible causes
Defective wiring
of the power
supply for
communication.
PWR LED is
1
OFF
Defective power
supply for
communication
Incorrect address
setting
Solenoid valve
failure
Connection
between SI unit
Solenoid
and manifold
valve
2
solenoid valve is
operation
defective.
failure
Excessive
number of
outputs
Solenoid valve
power supply
failure
Communication
failure
Communication
PWR LED is
line short
ON
circuited
COMM LED
3
is OFF
ERR LED is
ON
Broken
communication
line
Investigation method
Check the communication cable is not
broken, and confirm that the connection
between the power supply cable and
the terminal is not loose.
Confirm that repeated bending stress or
pulling force is not applied to the cable.
Confirm the wiring of the power supply
for communication is correct.
Confirm the supply voltage for the
power supply for communication.
Check the node address set to the SI
unit and program setting.
Check the operation by replacing the
solenoid valve. Or refer to
Troubleshooting of the solenoid valve.
Check that there is no contact failure
such as bending of the connector pins
between the SI unit and solenoid valve
manifold.
Check the total number of outputs of the
solenoid valves connected to the
manifold does not exceed the maximum
number of outputs of the SI unit.
Confirm the supply voltage for the
power supply for the solenoid valve.
Check that there is no equipment or
high voltage cables which generates
noise around the communication and
power supply cables.
Check the communication BDH and
BDL lines for short circuit.
Check that the cable for the
communication is not broken, and
confirm that the connection between the
communication cable and the terminal
is not loose.
Confirm that repeated bending stress or
pulling force is not applied to the cable.
-25-
Countermeasure
Connect the power cable
correctly.
Wire correctly.
Supply 24 VDC (14 to
26.4 VDC) for the power supply
for communication.
Set correctly.
Check the Troubleshooting of
the solenoid valve. Or contact
to the department in charge of
the solenoid valve
Connect the SI unit and the
solenoid valve manifold
correctly.
The number of outputs should
be not more than the maximum
number of outputs of the SI
unit.
Supply 24 VDC +10%/-5% for
the power supply for the
solenoid valve.
Separate the communication
line and power cable away
from noise sources.
Wire correctly.
Connect the communication
cable correctly.
No.EX※※-OMC0002-C