Refer to
Designing the Power Supply System
and
Wiring
in the user's manual for the connected
Communications Coupler Unit for details on Units to which I/O power is supplied in a Slave Termi-
nal.
Additional Information
NX-series Power Supply-related Units
The following three NX-series Units are related to power supply.
• Additional NX Unit Power Supply Units
• Additional I/O Power Supply Units
• I/O Power Supply Connection Units
Refer to
NX-series System Units User’s Manual (Cat. No. W523)
for the specifications of these
Units.
For a complete list of the latest power supply Units in the NX Series, refer to the product catalog
or OMRON website, or contact your OMRON representative.
4-2-3
Calculating the Total Current Consumption from I/O Power Sup-
ply
The total current consumption of I/O power supplied from the NX bus must be within the range of the
maximum I/O power supply current of the Communications Coupler Unit or the Additional I/O Power
Supply Unit. However, when an Additional I/O Power Supply Unit is connected to the CPU Rack of a
CPU Unit, the maximum I/O power supply current value may be smaller than that of the Additional I/O
Power Supply Unit. For example, the maximum I/O power supply current for the CPU Rack of an
NX1P2 CPU Unit is 4 A. Refer to the hardware user’s manual for the CPU Unit to which NX Units are
connected for information on the restrictions for the CPU Rack.
To confirm this and to calculate the I/O power supply capacity, calculate the total current consumption
of the I/O power supply from the NX bus.
Note that the current consumption from I/O power supply indicated in the data sheet for each Unit type
does not include the load current of any external connection load and current consumption of any con-
nected external devices.
The total current consumption from I/O power supply of the High-speed Analog Input Units is calculat-
ed as follows:
on page A - 2 for the current consumption from I/O power supply for each
High-speed Analog Input Unit model.
Precautions for Safe Use
The I/O power supply current for the CPU Rack with an NX-series CPU Unit should be within
the range specified for the CPU Unit model. For example, use the NX1P2 CPU Unit with a cur-
rent of 4 A or less. Using the currents that are outside of the specifications may cause failure or
corruption. Refer to the user’s manual for the connected CPU Unit for the I/O power supply cur-
rent for the CPU Unit model.
Total Current Consumption from I/O Power Supply from the NX Bus
The total current consumption from I/O power supply from the NX bus is the sum of the following: the
current consumption from I/O power supply of the NX Unit that supplies the I/O power from the NX
4 Installation and Wiring
4 - 5
NX-series Analog I/O Units User’s Manual for High-speed Analog Input Units (W592)
4-2 Power Supply T
ypes and W
iring
4
4-2-3
Calculating the T
otal Current Consumption from I/O Power Supply
