Omron sysmac NX Series User Manual page 108

4 Installation and Wiring
Precautions for Correct Use
Select an I/O power supply with sufficient capacity by considering the inrush current when the
power is turned ON. Sometimes, the I/O power supply may not be turned ON caused by inrush
current when the power is turned ON.
 Calculation Example for Power Supply Capacity of I/O Power Supply
An example of calculating the required power supply capacity of the I/O power supply is given be-
low.
a. Configuration and Conditions
Power Supply Unit
I/O power
supply
(24 VDC)
I/O power supply voltage
Inputs
Outputs
I/O power is supplied to the NX-ID3317 and NX-OD3121 from the NX bus.
b. Unit Specifications
Model
NX-PF0730
NX-ID3317
NX-OD3121
c. Calculations
The current consumption from the I/O power supply for each Unit is calculated as follows.
4-36
Digital Input
Additional I/O
Unit
NX-ID3317
NX-PF0730
Connected
input
devices
Item
Number of inputs used (that turn ON si-
multaneously)
Current consumption of connected input
devices
Number of outputs (that turn ON simulta-
neously)
Load current of connected loads
Current consumption of connected output
devices
Current consumption from I/O power
10 mA
0 mA
10 mA
Digital
Output Unit
NX-OD3121
End Cover
Connected
output
devices
(loads)
24 VDC
4 points
50 mA/point
4 points
125 mA/point
50 mA/point
supply
---
6 mA/point
---
NX-series System Units User's Manual (W523)
Condition
Input current