Omron CQM1H-SCB41 Operation Manual page 13

Application Precautions
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• 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.
• Always discharge static electricity by touching a grounded metal part
before mounting the Serial Communications Board.
• Always discharge static electricity by touching a grounded metal part
before connecting cable connectors to RS-232C or RS-422A/485 port of
the Serial Communications Board.
• Be sure that the connectors, terminal blocks, expansion cables, and other
items with locking devices are properly locked into place. Improper locking
may result in malfunction.
• Confirm that no adverse effect will occur in the system before attempting
any of the following. Not doing so may result in an unexpected operation.
• Changing the operating mode of the PC.
• Force-setting/force-resetting any bit in memory.
• Changing the present value of any word or any set value in memory.
• Take appropriate measures to ensure that the specified power with the
rated voltage and frequency is supplied. Be particularly careful in places
where the power supply is unstable. An incorrect power supply may result
in malfunction.
• Leave the label attached to the Unit when wiring. Removing the label may
result in malfunction if foreign matter enters the Unit.
• Remove the label after the completion of wiring to ensure proper heat dis-
sipation. Leaving the label attached may result in malfunction.
• Confirm polarities before connecting RS-422A/485 cables. Some devices
require that SDA/B and RDA/B or signal polarities be reversed.
• Double-check all wiring and switch settings before turning ON the power
supply. Incorrect wiring may result in burning.
• Check the user programming (ladder program, protocol macro data, etc.)
for proper execution before actually running it on the Unit. Not checking
the program may result in an unexpected operation.
• Resume operation only after transferring to the new CPU Unit the con-
tents of the DM Area, HR Area, and other data required for resuming
operation. Not doing so may result in an unexpected operation.
• Circuit boards have sharp or pointed edges, such as those on the leads of
electrical parts. Do not touch the back of printed boards or mounted sec-
tions with your bare hands.
• Connect or set terminating resistance correctly when using RS-422A/485
cables.
• During transportation and storage, cover the circuit boards with conduc-
tive materials to prevent them from being damaged by static electricity
caused by LSIs or ICs and keep them within the specified storage temper-
ature.
• Refer to Section 2 Board Components and Installation and correctly wire
and install the Units.
• Do not attempt to take any Units apart, to repair any Units, or to modify
any Units in any way.
• Disconnect the functional ground terminal when performing withstand
voltage tests. Not disconnecting the functional ground terminal may result
in burning.
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