Omron CS1W-LC001 Operation Manual page 16

Safety Precautions
WARNING
WARNING
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The PC outputs may remain ON or OFF due to deposition or burning of
the output relays or destruction of the output transistors. As a
countermeasure for such problems, external safety measures must be
provided to ensure safety in the system.
When the 24-VDC output (service power supply to the PC) is overloaded
or short-circuited, the voltage may drop and result in the outputs being
turned OFF. As a countermeasure for such problems, external safety
measures must be provided to ensure safety in the system.
Check the following items before starting to run the Loop Control Unit:
Analog Input/Output Units used in combination with the Loop Control Unit
must be mounted correctly, and the unit number set on the front panel of
the Analog Input/Output Unit must match the unit number set on the Field
Terminal block. If the unit numbers do not match, input/output (read/write)
is performed on the data of another Special I/O Unit (whose unit number
is set on the Field Terminal block).
The defaults of the System Common block on the Loop Control Unit must
be set correctly. In particular, make sure that the Data Memory (D) for the
Node Terminals on the CPU Unit used by the Loop Control Unit is not set
in duplicate for other applications on the PC. If the application of the Data
Memory is set in duplicate, the PC system may act unexpectedly and
cause injury.
When writing data to the I/O memory in the CPU Unit with function blocks
(e.g., using Send All Blocks, Expanded DO/AO Terminal to CPU Unit, or
DO/AO Terminal to CPU Unit), be sure that the words written to in the I/O
memory are not being used for any other purpose. If I/O memory words
are allocated to more than one purpose, the PC system may act
unexpectedly and cause injury.
Do not perform processing in such a way that the Loop Control Unit and
CPU Unit perform writing on identical I/O memory addresses allocated to an
contact output or analog output to an external Unit. If writing is performed on
identical addresses, the externally connected load may act unexpectedly
and cause injury.
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