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5 Designing the Power Supply System
NX-series EtherNet/IP Coupler Unit User’s Manual (W536)
5-3 Designing the I/O Power Supply System
5
5-3-2 Designing the I/O Power Supply from the NX Bus
Maximum I/O Power Supply Current
The maximum I/O power supply current is the maximum current that the I/O power supply that is
connected to the EtherNet/IP Coupler Unit or Additional I/O Power Supply Unit can supply through
the NX bus connectors to the NX Units. For the maximum I/O power supply current of the Ether-
Net/IP Coupler Unit, refer to 3-1-2 EtherNet/IP Coupler Unit Specifications on page 3-3. For the
maximum I/O power supply current of the Additional I/O Power Supply Unit, refer to the NX-series
System Units User’s Manual (Cat. No. W523).
The total current consumption from the I/O power supply from the NX bus is the total of the following
current consumptions.
• The current consumption from the I/O power supply that is required for the EtherNet/IP Coupler Unit
or the Additional I/O Power Supply Unit, and for the NX Units that are connected to the EtherNet/IP
Coupler Unit or Additional I/O Power Supply Unit
• The current consumption between the NX Units and the connected external devices
Calculating the Total Current Consumption from the I/O Power Sup-
ply
Current consumption item Description
Current consumption from I/O
power supply
This is the current that is consumed by the internal circuits that operate on
the I/O power supply.
Specific values are given in the user’s manuals for individual Units.
●The total current consumption from the I/O
power supply must not exceed the
maximum current of the I/O power supply.
(NX Units that are supplied power from
external sources are not included in the
calculation.)
●The voltage drop in the I/O power supply
must be within the voltage specifications
of the I/O circuits of the NX Units and the
connected external devices.
NX Units
●The total current consumption
from the I/O power supply
must not exceed the
maximum current of the I/O
power supply.
●The voltage drop in the I/O
power supply must be within
the voltage specifications of
the I/O circuits of the NX
Units and the connected
external devices.
●The total current consumption
from the I/O power supply
must not exceed the
maximum current of the I/O
power supply.
●The voltage drop in the I/O
power supply must be within
the voltage specifications of
the I/O circuits of the NX
Units and the connected
external devices.
Additional I/O Power Supply Unit
NX Units
Additional I/O Power Supply Unit
NX Units
End Cover
To external
devices
To external
devices
To external
devices
To external
devices
I/O power
supply
Separating the I/O
Power Supply
• The Additional I/O
Power Supply Unit is
used because
different I/O power
supply voltages are
used.
The Additional I/O Power
Supply Unit is used because
otherwise the maximum
current of the I/O power supply
would be exceeded.
I/O power
supply
I/O power
supply
terminals
I/O power
supply
terminals
I/O
power
supply
I/O
power
supply
Supplied from
external source.
I/O power
supply
I/O power supply
terminals
EtherNet/IP
Coupler Unit