Mitsubishi Electric MELSEC iQ-F Series User Manual page 7

[STARTUP AND MAINTENANCE PRECAUTIONS]
CAUTION
● When connecting an external device with a CPU module or 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,
parameter change, forced output, or operating status change) of a running programmable controller,
read the relevant manuals carefully and ensure that the operation is safe before proceeding. Improper
operation may damage machines or cause accidents.
● 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.
● Do not disassemble or modify the PLC. Doing so may cause fire, equipment failures, or malfunctions.
For repair, contact your local Mitsubishi Electric representative.
CAUTION
● Turn off the power to the PLC before attaching or detaching the following devices. Failure to do so
may cause equipment failures or malfunctions.
- Peripheral devices, expansion board, expansion adapter, and connector conversion adapter
- Extension modules, bus conversion module, and connector conversion module
- Battery
● Read relevant manuals carefully and ensure the safety before performing online operations (operation
status change) with peripheral devices connected to the CPU modules of other stations. Improper
operation may damage machines or cause accidents.
[OPERATION PRECAUTIONS]
CAUTION
● Construct an interlock circuit in the program so that the whole system always operates on the safe
side before executing the control (for data change) of the PLC in operation.
Read the manual thoroughly and ensure complete safety before executing other controls (for program
change, parameter change, forcible output and operation status change) of the PLC in operation.
Otherwise, the machine may be damaged and accidents may occur by erroneous operations.
● Do not power off the CPU module or reset the CPU module while the setting values in the buffer
memory are being written to the flash ROM in the intelligent function module. Doing so will make the
data in the flash ROM card undefined. The values need to be set in the buffer memory and written to
the flash ROM again. Doing so can cause malfunction or failure of the module.
● Note that the whole system may not be reset by the RUN/STOP/RESET switch when the CPU module
or intelligent function module detects an error, such as a watchdog timer error, during self-diagnosis.
In such cases, turn the power off and on again.
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