Mitsubishi Electric MELSEC-Q series Programming Manual page 4

[Design Precautions]
WARNING
● When connecting a peripheral with the CPU module or connecting an external device, such as a
personal computer, with an intelligent function module to modify data of a running programmable
controller, configure an interlock circuit in the program to ensure that the entire system will always
operate safely. For other forms of control (such as program modification or operating status change)
of a running programmable controller, read the relevant manuals carefully and ensure that the
operation is safe before proceeding. Especially, when a remote programmable controller is controlled
by an external device, immediate action cannot be taken if a problem occurs in 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.
[Startup and Maintenance Precautions]
CAUTION
● Before performing online operations (especially, program modification, forced output, and operating
status change) for the running CPU module from the peripheral connected, read relevant manuals
carefully and ensure the safety. Improper operation may damage machines or cause accidents.
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