3. Cabling
3-65
TI 32P01J10-01EN
Apr. 26, 2017-00
Connecting Wiring Check Adapters
Connect the wiring check adapters to detect disconnected or short-circuited field wiring between
the digital input module and field equipment. These adapters should be connected at the field
equipment side. The two types of these adapters are:
• SCB100: Disconnection detection while accepting an OFF signal
If this type of adapter is connected in parallel with a sensor switch, a disconnection occurring
while accepting an OFF signal can be detected.
• SCB110: Short-circuit detection
If this type of adapter is connected in series with a sensor switch, a short-circuit in the power
line, occurring while accepting an ON signal, or a short-circuit with other channels can be
detected. In addition to the above wiring check adapters, input module’s diagnostic functions
should be able to detect disconnections or short-circuits.
SEE
ALSO
For more information about diagnostic features of the input modules, see the following:
Appendix 1.3.4 “Setting for the DI channel” of the Engineering Guide Vol. 1 (IM 32P01C10-01EN).
S
hape of Wiring Check Adapters
The following figure shows the shape of the SCB100 and SCB110.
F030620.ai
Figure External View of SCB100 and SCB110
C
onnecting Wiring Check Devices
F030621.ai
DCn
INn
SDV144
SCB100
Detect disconnection
when input is OFF
Detect short circuit
when input is ON
Detect disconnection
and short circuit
DCn
INn
SDV144
SCB110
DCn
INn
SDV144
Red
Blue
Red
Blue
SCB100
SCB110
: The field equipment switch
Figure Connecting Wiring Check Adapters
IMPORTANT
• Connect the SCB110 with correct polarity. If it is connected incorrectly, no detection can be
made.
• To detect short-circuits or disconnections in the field wiring effectively, locate the adapters
in the vicinity of the field equipment. Also install these adapters in a location out of direct
sunlight and sheltered from rain.
• Be careful not to bend a covered part.