NX Unit Power Supply vs. I/O Power Supply

The power supply system for the CPU Rack of the NX-series CPU Unit consists of two power supply lines: one for NX Unit power and the other for I/O power.

The Unit Power Supply provides power for the internal circuits of the CPU Unit, as well as NX Unit power for the NX Units. Up to 10 W of NX Unit power can be delivered to NX Units via the power supply terminals on the CPU unit.

The I/O Power Supply provides power to the I/O circuits of each NX Unit on the CPU Rack, as well as to external devices connected to the NX Units. Some NX Units receive I/O power through the NX bus, and others receive from external devices. 

You may need additional power supply Units for NX Unit power or I/O power according to the total power consumption or the total current consumption of NX Units on the CPU Rack.

NX Unit Power supply requirement (NX-PD____)

Each NX unit added to the rack draws a certain amount of power from the NX bus for its internal circuits. For example, the NX-ID5142-1 draws 0.85W per unit. 

If the total power drawn by the units on the rack exceed the available NX Unit power provided by the NX bus, SYSMAC Studio will display a warning sign in the CPU Rack page:

Use an extra NX Unit Power supply (NX-PD) to add another 10W to the available NX Unit power supply.

I/O Power supply requirement (NX-PF____)

If any NX Unit on the CPU Rack receives I/O power through the NX bus, you need to prepare an external I/O power supply device. Add one or more NX-PF Additional I/O Power Supply Units when I/O power is supplied from the NX bus to NX Units connected to the CPU Unit. 

Please note that SYSMAC Studio does not display any warning when the I/O Power supply requirements are not met.

More information

Find more information in the CPU hardware manual of your CPU: Section 4 Designing the Power Supply System.

NX1P2: Nx-Series Nx1P2 Cpu Unit Hardware Users Manual En.Pdf (W578)

NX102: Nx102 Cpu Unit Technical Manual En.Pdf (W593)