4 - 11
4 Installation and Wiring
NX-series Analog I/O Units User’s Manual for Analog Input Units and Analog Output Units (W522)
4-
2 Pow
er Supp
ly T
ypes a
nd Wiring
4
4-
2-2 C
alculating
the T
o
ta
l C
urr
ent
Consumption from
I/O Pow
er Supply
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, for a CPU Rack, the specification for the maximum I/O power supply current is
restricted regardless of the model of the Additional I/O Power Supply Unit. 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
from I/O power supply from the NX bus.
The total current consumption from I/O power supply from the NX bus is the total sum of current con-
sumption from I/O power supply of the NX Unit that supplies the I/O power from the NX bus, the current
of each applicable I/O circuit, and current consumption of any connected external devices.
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 Analog Input Units and Analog Output Units
is calculated as follows:
z
Total Current Consumption from I/O Power Supply of the Analog Input Units
= (Current consumption from I/O power supply of the Analog Input Units) + (Total current consump-
tion of connected external devices)
z
Total Current Consumption from I/O Power Supply of the Analog Output Units
= (Current consumption from I/O power supply of the Analog Output Units) + (Total current con-
sumption of connected external devices)
on page A-2 for the current consumption from the I/O power supply for the indi-
vidual Analog Input Units and Analog Output Units.
Precautions for Safe Use
Use the I/O power supply current for the CPU Rack of the NX-series NX1P2 CPU Unit at 4 A or
less. Using the currents that are outside of the specifications may cause failure or damage.
4-2-2
Calculating the Total Current Consumption from I/O Power Sup-
ply
Summary of Contents for NX-AD series
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