Safety Precautions - Mitsubishi Electric MELSEC Q Series Reference Manual

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 precautions given in this manual are concerned with this product only. For the safety precautions of
the programmable controller system, refer to the user's manual for the CPU module used.
In this manual, the safety precautions are classified into two levels: "
WARNING
CAUTION
Under some circumstances, failure to observe the precautions given under "
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]
• When the network develops a communication error, the station with the communication error will
enter into the following status.
Check the communication status information and configure an interlock circuit in the sequence
program to ensure that the entire system will operate safely. Failure to do so may result in an
accident due to an incorrect output or malfunction.
(1) The remote master station will hold the data from before the communication error.
(2) The remote I/O station turns off all outputs. The output module of the remote I/O station can
clear/hold the output status at the time of error by using the remote I/O module parameters.
As the parameters are set to "clear" by default, the output module turns off the outputs at the
time of error. If it is required to hold the output in order to operate the system safely, set the
parameters to "hold".
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• SAFETY PRECAUTIONS •
(Read these precautions before using this product.)
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.
WARNING
!
WARNING" and "
CAUTION" may lead to
CAUTION".
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