Omron NXR Series User Manual page 87

= (Iui3) + (Io3)
≈ 2.23 A
The sum of the current consumption of each Unit supplied from external power supplies is calculat-
ed as follows.
(Iui1 + Iui2 + Iui3 + Io1 + Io2 + Io3)
= (3.30 A + 2.23 A + 2.23 A)
= 7.76 A
This example is acceptable because the calculation result is below 9 A, the maximum power supply
current of the IO-Link Master Unit ILM1.
Calculating the Voltage Drop in Power Supply with Through-wiring
When the power supply method is power supply with through-wiring, voltage drop occurs due to the
following elements.
• Internal circuits of IO-Link Master Units
• Power supply cables
When the power supply method is power supply with through-wiring, the current to be consumed by
other IO-Link Master Units flows through each IO-Link Master Unit, which causes voltage drop in the
internal circuits of the Units.
Voltage drop in the internal circuits of IO-Link Master Units and power supply cables is calculated as a
sum of the total current consumption from the Unit/input power supply and output power supply, as
shown in the table below.
Sum of total current con-
sumption from Unit/input
power supply and output
power supply (A)
9
8
6
4
3
2
1
 Calculation Example for Voltage Drop
The following example explains how to calculate voltage drop under the following conditions.
Item
Configuration
Application
conditions for
connected ex-
ternal devices
NXR-series IO-Link Master Unit for EtherCAT User's Manual (W640)
Voltage drop in
the internal cir-
cuits of Unit (V)
0.54
0.48
0.36
0.24
0.18
0.12
0.06
Use the conditions specified in Calculation Example for the Total Current Consumption in
Power Supply with Through-wiring on page 4-15.
4 Designing the Power Supply System
Voltage drop for each power supply cable length (V)
1 m 3 m
0.90 1.53
0.80 1.36
0.60 1.02
0.40 0.68
0.30 0.51
0.20 0.34
0.10 0.17
Conditions
5 m 10 m
2.07 3.60
1.84 3.20
1.38 2.40
0.92 1.60
0.69 1.20
0.46 0.80
0.23 0.40
4-17
4