Omron NX-ID User Manual page 129

Countermeasure 2
Mount a limiting resistor.
When I/O power is supplied from the NX bus, the method is as shown in the following figure.
NPN type
Communications
Coupler Unit or
Additional I/O Power
Supply Unit
Transistor Output Unit
When I/O power is supplied from an external source, the method is as shown in the following figure.
NPN type
Transistor Output Unit
In countermeasure 1, the current consumption from I/O power supply is increased although the voltage
supplied to the load L is not decreased.
In countermeasure 2, the voltage supplied to the load L is decreased although the current consumption
from I/O power supply is not increased.
Select the appropriate countermeasures according to the operating conditions.
NX-series Digital I/O Unit User's Manual (W521)
IOV
IOG
IOV
L
OUT
IOG
R
OUT L
+
COM
4 Installation and Wiring
PNP type
Communications IOV
Coupler Unit or
Additional I/O Power
IOG
Supply Unit
IOV
OUT
Transistor Output Unit
IOG
PNP type
COM
Transistor Output Unit
OUT
L
4
+
R
L
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