5 Installation and Wiring
5 - 10
NX-series Safety Control Unit User’s Manual (Z930)
Additional I/O
Power Supply Unit
This NX Unit provides additional I/O power supply.
Use this NX Unit in the following cases.
(a) When the I/O power supply capacity is insufficient
• When the total current consumption for the I/O power supply exceeds the maximum I/O
power supply current of the EtherCAT Coupler Unit
• When a voltage drop in the I/O power supply causes the voltage of the I/O power supply
to go below the voltage specifications of the I/O circuits or connected external devices
(b) Separating the I/O Power Supply
• When connected external devices have different I/O power supply voltages
• When separating the power supply systems
Name Function
I/O power
supply
Unit power
supply
Case (a)
Case (b)
Communications
Coupler Unit
Separated by Additional
I/O Power Supply Unit
Separated by Additional
I/O Power Supply Unit
Additional I/O Power Supply UnitAdditional I/O Power Supply Unit
NX Unit
Communications
Coupler Unit
NX Unit
Separated by Additional I/O Power Supply Unit.Separated by Additional I/O Power Supply Unit.
Additional I/O Power Supply UnitAdditional I/O Power Supply Unit
I/O power
supply
I/O power
supply
I/O power
supply
Unit power
supply
When the I/O power supply becomes
the following states for the subsequent NX
Units.
• When it exceeds the maximum I/O power
supply current
• When it goes below the voltage specifica-
tions of the connected external devices
• When different I/O power supply voltages are used.
• When separating the power supply systems.
Internal
power
supply
circuits
Internal
power
supply
circuits