Mitsubishi MELSEC LJ71C24, User Manual

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SAFETY PRECAUTIONS
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(Read these precautions before using this product.)
Before using this product, please read this manual and the relevant manuals carefully and pay full
attention to safety to handle the product correctly.
The instructions given in this manual are concerned with this product. For the safety instructions of the
programmable controller system, please read the user's manual of the CPU module to use.
In this manual, the safety precautions are classified into two levels: "
!
WARNING" and "
!
CAUTION".
Indicates that incorrect handling may cause hazardous conditions,
resulting in death or severe injury.
Indicates that incorrect handling may cause hazardous conditions,
resulting in minor or moderate injury or property damage.
Under some circumstances, failure to observe the precautions given under "
!
CAUTION" may lead to
serious consequences.
Observe the precautions of both levels because they are important for personal and system safety.
Make sure that the end users read this manual and then keep the manual in a safe place for future
reference.
[Design Precautions]
!
WARNING
•
For the operation status of each station at communication error in each station, refer to the
respective manual for each station.
The communication error may result in an accident due to incorrect output or malfunction.
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When changing data of a running programmable controller from a peripheral connected to the
CPU module or from an external device such as a personal computer connected to an intelligent
function module, configure an interlock circuit in the program to ensure that the entire system
will always operate safely.
For other controls to a running programmable controller (such as program modification or
operating status change), read relevant manuals carefully and ensure the safety before the
operation.
Especially, in the case of a control from an external device to a remote programmable controller,
immediate action cannot be taken for a problem on the programmable controller due to a
communication failure. To prevent this, configure an interlock circuit in the program, and
determine corrective actions to be taken between the external device and CPU module in case
of a communication failure.
!
WARNING
!
CAUTION