17
  Safety Precautions
NX-series EtherNet/IP Coupler Unit User’s Manual (W536)
Voltage and Current Inputs
Make sure that the voltages and currents that are input to the Units and slaves are within 
the specified ranges.
Inputting voltages or currents that are outside of the specified ranges may cause accidents 
or fire.
Transferring
Always confirm safety at the destination node before you transfer Unit configuration infor-
mation, parameters, settings, or other data from tools such as the Sysmac Studio.
The devices or machines may operate unexpectedly, regardless of the operating mode of 
the Controller.
Cautions
Wiring
When you connect a computer or other peripheral device to a Communications Coupler 
Unit that has a non-isolated DC power supply, either ground the 0-V side of the external 
power supply (i.e. Unit power supply) or do not ground it at all.
If the peripheral devices are grounded incorrectly, the external power supply (i.e. Unit 
power supply) may be short-circuited.
Never ground the 24-V side of the power supply, as shown in the following figure.
Be sure that all terminal screws and cable connector screws are tightened to the torque 
specified in the relevant manuals. The loose screws may result in fire or malfunction.
Peripheral device 
(e.g., computer)
Non-isolated DC power 
supply (internal power 
supply circuit)
24 V
0 V
Peripheral device 
cable
Ground terminal
Communications Coupler Unit
NX Unit power 
supply
Unit power 
supply