Mitsubishi FX3U Series User Manual page 3

Before installing, operating, maintenance or inspecting this product, thoroughly read and understand this
manual and the associated manuals. Also pay careful attention to handle the module properly and safety.
This manual classifies the safety precautions into two categories:
Depending on circumstances, procedures indicated by
In any case, it is important to follow the directions for usage.
Store this manual in a safe place so that you can take it out and read it whenever necessary. Always forward
it to the end user.
1. DESIGN PRECAUTIONS
• Provide a safety circuit on the outside of the PLC so that the whole system operates to ensure the safety even
when external power supply trouble, PLC failure, or communication error occurs.
Otherwise, malfunction or output failures may result in an accident.
1) An emergency stop circuit, a protection circuit, an interlock circuit for opposite movements, such as normal
and reverse rotations, and an interlock circuit for preventing damage to the machine at the upper and lower
positioning limits should be configured on the outside of the PLC.
2) When the PLC CPU detects an error, such as a watchdog timer error, during self-diagnosis, all outputs are
turned off. When an error that cannot be detected by the PLC CPU occurs in an input/output control block,
output control may be disabled.
Design external circuits and mechanisms to ensure safe operations of the machine in such a case.
3) The output current of the service power supply for sensor varies depending on the model and the absence/
presence of extension blocks. If overload is applied, the voltage automatically drops, inputs in the PLC are
disabled, and all outputs are turned off.
Design external circuits and mechanisms to ensure safe operations of the machine in such a case.
4) When some sort of error occurs in a relay, triac or transistor of the output unit, output may be kept on or off.
For output signals that may lead to serious accidents, design external circuits and mechanisms to ensure safe
operations of the machine in such cases.
• Do not bundle the control line together with the main circuit or power line. Do not lay the control line near them.As
a rule, lay the control line at least 100mm(3.94") or more away from the main circuit or power line.
Noise may cause malfunctions.
• Use the product in such a status that excessive force is not applied on the built-in programming board, power
connectors, I/O connectors, communication connectors, and communication cables.
Failure to do so may result in wire breakage or failure of the PLC.
Safety Precautions
(Read these precautions before use.)
Indicates that incorrect handling may cause hazardous conditions, resulting in
death or severe injury.
Indicates that incorrect handling may cause hazardous conditions, resulting in
medium or slight personal injury or physical damage.
(1)
and
may also be linked to serious results.
.