Omron NSJ CONTROLLERS - 03-2008 Operation Manual page 21

Safety Precautions
!Caution The NSJ Controller automatically backs up the user program and parameter
!Caution When installing the NSJ Controller on the door of a control panel or any other
!Caution Tighten the power supply terminal block screws to the torque specified in this
!Caution Wire the polarity of the power supply correctly when using a DC power supply.
!Caution Do not touch a Power Supply Unit while power is being supplied or immedi-
!Caution When connecting a Programming Device or other personal computer to a NSJ
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data to flash memory when these are written to the Controller Section. I/O
memory (including the DM, EM, and HR Areas), however, is not written to
flash memory. The DM, EM, and HR Areas can be held during power interrup-
tions with a battery. If there is a battery error, the contents of these areas may
not be accurate after a power interruption. If the contents of the DM, EM, and
HR Areas are used to control external outputs, prevent inappropriate outputs
from being made whenever the Battery Error Flag (A40204) is ON. Areas
such as the DM, EM, and HR Areas, the contents of which can be held during
power interrupts, is backed up by a battery. If a battery error occurs, the con-
tents of the areas that are set to be held may not be accurate even though a
memory error will not occur to stop operation. If necessary for the safety of the
system, take appropriate measures in the ladder program whenever the Bat-
tery Error Flag (A40204) turns ON, such as resetting the data in these areas.
moving object, be sure that all cables are long enough so that excessive force
is not applied to cables and connectors.
manual. Loose screws may result in fire or malfunction.
Reversing the polarity may cause abnormal operation.
ately after turning OFF the power supply. The Unit may be hot and may cause
burns.
Controller to which a non-insulated Power Supply Unit (e.g., CJ1W-PD022) is
mounted, either ground the 0 V side of the external power supply or do not
ground the external power supply at all ground. A short-circuit will occur in the
external power supply if incorrect grounding methods are used. Never ground
the 24 V side, as shown below.
Wiring in Which the 24-V Power Supply Will Short
Non-insulated
CJ1W-SCU
DC power supply
24 V
or other Unit
0 V
Expansion Rack
FG
Peripheral
cable
0 V
Peripheral device (e.g.,
personal computer)
3