Cautions - Omron NX Series Hardware User Manual

Cautions

Application
Do not touch any Unit when power is being supplied or immediately after the power
supply is turned OFF. Doing so may result in burn injury.
Wiring
Be sure that all terminal screws and cable connector screws are tightened to the tor-
que specified in the relevant manuals. Loose screws may result in fire or malfunction.
When you connect a computer or other peripheral device to a Controller that has a
non-isolated DC power supply, either ground the 0-V side of the external power supply
for the Unit power supply or do not ground it at all.
If the peripheral devices are grounded incorrectly, the external power supply for the
Unit power supply may be short-circuited. Never ground the 24-V side of the power
supply, as shown in the following figure.
Unit power
supply
terminals
External power supply (Unit power supply)
Online Editing
Execute online editing only after confirming that no adverse effects will be caused by
deviations in the timing of I/O. If you perform online editing, the task execution time
may exceed the task period, I/O may not be refreshed with external devices, input sig-
nals may not be read, and output timing may change.
NX-series NX502 CPU Unit Hardware User's Manual (W629)
Caution
Non-isolated type Communications Interface Unit, etc.
CPU Unit
Non-isolated DC
power supply
Internal
power supply
circuit
(No-isola-
tion)
External device
(e.g. computer)
Cable
Safety Precautions
19