Omron NX-SL5500

3-2
Power Supply Types and Wiring
There are the following two types of power supplies that supply power to the NX Units.
Power supply
type
Description
Unit power supply This power supply is used for operating the NX Units.
I/O power supply This power supply is used for driving the I/O circuits of the NX Units and for the connected external devi-
ces.
The method for supplying power to the NX Units and the wiring method depend on the specifications
for the CPU Unit to which NX Units are connected or the specifications for the Slave Terminal. Refer to
Designing the Power Supply System or
Wiring, which are described both in the hardware user's man-
ual for the CPU Unit to which NX Units are connected and user's manual for the Communications
Coupler Unit, for details on the method for supplying power to the NX Units and the wiring method.
The subsequent sections describe the applications of I/O power supply for the Safety Control Unit and
supply methods, and how to calculate the total current consumption from the I/O power supply.
3-2-1
Applications of I/O Power Supply and Supply Methods
The applications of I/O power supply and supply methods for the Safety Control Unit are given as fol-
lows. Note that the Safety Control Unit does not use I/O power supply
.
Applications of I/O Power Supply
The I/O power supply is used for the following applications.
• Driving the I/O circuits of the Safety Input Unit or Safety Output Unit
•
Input current to the Safety Input Unit
• Load current of external loads of Safety Output Unit
• Power for connected external devices
I/O Power Supply Methods
I/O power is supplied to a Safety Control Unit from the NX bus.
This power is supplied through the NX bus connectors by connecting an I/O power supply to the I/O
power supply terminals on the Communications Coupler Unit or Additional I/O Power Supply Unit.
Refer to Designing the Power Supply System and Wiring
in the hardware user’s manual for the con-
nected CPU Unit for details on Units to which I/O power is supplied in a CPU Rack.
Refer to Designing the Power Supply System and Wiring in the user's manual for the connected Com-
munications Coupler Unit for details on Units to which I/O power is supplied in a Slave Terminal.
3 Installation and Wiring
3 - 8
NX-series Safety Control Unit User's Manual (Z930)