Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 33

Safety Precautions
!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
!Caution Execute online edit only after confirming that no adverse effects will be
!Caution The CS1-H, CJ1-H, CJ1M, and CS1D CPU Units automatically back up the
!Caution Confirm safety at the destination node before transferring a program to
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.
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.
• Emergency stop circuits, interlock circuits, limit circuits, and similar safety
measures must be provided in external control circuits.
• The PLC will turn OFF all outputs when its self-diagnosis function detects
any error or when a severe failure alarm (FALS) instruction is executed.
As a countermeasure for 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 counter-
measure 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 over-
loaded 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.
caused by extending the cycle time. Otherwise, the input signals may not be
readable.
user program and parameter data to flash memory when these are written to
the CPU Unit. 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 interruptions 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 inap-
propriate outputs from being made whenever the Battery Error Flag (A40204)
is ON.
another node or changing contents of the I/O memory area. Doing either of
these without confirming safety may result in injury.
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