Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 25

Safety Precautions
!WARNING
!WARNING
!WARNING
!WARNING
!WARNING
!WARNING
!Caution Confirm safety before transferring data files stored in the file memory (Mem-
!Caution Fail-safe measures must be taken by the customer to ensure safety in the
Do not touch any of the terminals or terminal blocks while the power is being
supplied. Doing so may result in electric shock.
Do not attempt to disassemble, repair, or modify any Units. Any attempt to do
so may result in malfunction, fire, or electric shock.
Do not touch the Power Supply Unit while power is being supplied or immedi-
ately after power has been turned OFF. Doing so may result in electric shock.
Provide safety measures in external circuits (i.e., not in the Programmable
Controller), including the following items, to ensure safety in the system if an
abnormality occurs due to malfunction of the PLC or another external factor
affecting the PLC operation. Not doing so may result in serious accidents.
With a CS1D System operating in Duplex Mode, operation will be stopped
and all outputs will be turned OFF in the following circumstances.
• When self-diagnosis simultaneously detects an error in both the active
and standby CPU Units.
• When a severe failure alarm (FALS) instruction is simultaneously exe-
cuted in both the active and standby CPU Units.
• When self-diagnosis detects an error in Simplex Mode or when it detects
an error during duplex initialization for Duplex Mode.
• When a severe failure alarm (FALS) instruction is executed in Simplex
Mode or during duplex initialization for Duplex Mode.
Unexpected operation, however, may still occur for errors in the I/O control
section, errors in I/O memory, and other errors that cannot be detected by the
self-diagnosis function. As a countermeasure for all such errors, external
safety measures must be provided to ensure safety in the system.
The PLC 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-V DC output (service power supply to the PLC) 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.
ory Card or EM file memory) to the I/O area (CIO) of the CPU Unit using a
peripheral tool. Otherwise, the devices connected to the output unit may mal-
function regardless of the operation mode of the CPU Unit.
event of incorrect, missing, or abnormal signals caused by broken signal lines,
momentary power interruptions, or other causes. Serious accidents may
result from abnormal operation if proper measures are not provided.
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