Omron CPM2C Operation Manual page 18

Application Precautions
!Caution Failure to abide by the following precautions could lead to faulty operation of
the PC or the system, or could damage the PC or PC Units. Always heed
these precautions.
• Fail-safe measures must be taken by the customer to ensure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal
lines, momentary power interruptions, or other causes.
• Use the correct power supply voltage.
• Construct a control circuit so that power supply for the I/O circuits does
not come ON before power supply for the Unit. If power supply for the I/O
circuits comes ON before power supply for the Unit, normal operation may
be temporarily interrupted.
• If the operating mode is changed from RUN or MONITOR mode to PRO-
GRAM mode, with the IOM Hold Bit ON, the output will hold the most
recent status. In such a case, ensure that the external load does not
exceed specifications. (If operation is stopped because of an operation
error (including FALS instructions), the values in the internal memory of
the CPU Unit will be saved, but the outputs will all turn OFF.)
• For models with only the super-capacitor installed, the contents of the
READ/WRITE enable area of the DM area, HR area, AR area, and CNT
data area may be damaged if the power is turned OFF for a long time. To
prevent such damage, provide ladder program that will check AR 1314 in
order to ensure proper operation of the system.
• The life expectancy of the output relay varies considerably according to its
switching capacity and switching conditions. If the output relay is used
beyond its life expectancy, its contacts may become fused or burned.
• Install the Units properly so that they will not fall off.
• Be sure that all the mounting screws, terminal screws, and cable connec-
tor screws are tightened to the torque specified in the relevant manuals.
Incorrect tightening torque may result in malfunction.
• Be sure that the terminal blocks and other items with locking devices are
properly locked into place. Improper locking may result in malfunction.
• Be sure that terminal blocks and connectors are connected in the speci-
fied direction with the correct polarity. Not doing so may result in malfunc-
tion. If the power supply for the I/O circuits is turned ON with the input and
output connectors reversed, the fuse of output transistor may be blown.
• Use the Unit with the battery housing cover in place to prevent dust or for-
eign matter from entering inside the Unit. Not doing so may result in mal-
function.
• Install the expansion I/O connector cover to the last Unit (Expansion Unit
or Expansion I/O Unit) to prevent dust or foreign matter from entering
inside the Unit. Not doing so may result in malfunction.
• Be sure to attach the labels supplied with the CPM2C or provide other
protective covers when wiring in order to prevent dust or wiring cuttings
from entering the Unit.
• Remove the label after the completion of wiring to ensure proper heat dis-
sipation. Leaving the label attached may result in malfunction.
• Use round crimp terminals for wiring the AC power supply input to the AC
Power Supply Unit (CPM2C-PA201). For wiring the ground terminals or
power supply service terminals, use crimp terminals or solid wires. Do not
connect bare stranded wires directly to terminals. Connection of bare
stranded wires may result in burning.
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