Current consumption item Description
Current consumption between the NX
Units and the connected external de-
vices
This is the current that is consumed between the NX Units and the connected exter-
nal devices.
For example, this is the current consumed by a Digital Input Unit to supply power to
photoelectric sensors or to turn ON the input circuits in the Digital Input Unit.
The current consumption depends on the type of I/O circuit in the NX Unit, the num-
ber of I/O points that are used, and the current consumption of the connected exter-
nal device. It must be calculated for each NX Unit.
l
Calculation Example of I/O Power Supply Capacity
An example of calculating the required power supply capacity of the I/O power supply is given be-
low.
Configuration and Conditions
I/O
power
supply
(24 VDC)
Additional I/O Power
Supply Unit
NX-PF0730
End Cover
Digital Input
Unit
NX-ID3317
Connected
input
devices
Digital Output
Unit
NX-OD3121
Connected
output
devices
(loads)
Item Condition
I/O power supply voltage 24 VDC
Inputs Number of inputs used (that turn ON simultaneously) 4 points
Current consumption of connected input devices 50 mA/point
Outputs Number of outputs (that turn ON simultaneously) 4 points
Load current of connected loads 125 mA/point
Current consumption of connected output devices 50 mA/point
I/O power is supplied to the NX-ID3317 and NX-OD3121 from the NX bus.
a. Unit Specifications
Model Current consumption from I/O power supply Input current
NX-PF0730 10 mA ---
NX-ID3317 0 mA 6 mA/point
NX-OD3121 10 mA ---
b. Calculations
The current consumption from the I/O power supply for each Unit is calculated as follows.
NX-PF0730 Current Consumption = Current consumption from I/O power supply
= 10 mA
4 Designing the Power Supply System
4-17
NX-series NX502 CPU Unit Hardware User's Manual (W629)
4-3 Designing the I/O Power Supply System
4
4-3-2 Designing the I/O Power Supply from the NX Bus
To Next Page
Loading...
