Omron CJ1W-PRT21 Operation Manual page 23

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 torque specified in the relevant manuals. The loose screws may result in
fire or malfunction.
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 signals may not be read, and output timing may
change.
CJ-series PROFIBUS Slave Unit Operation Manual for NJ-series CPU Unit (W510)
Caution
21