Mitsubishi Electric MELSEC FX Series User Manual page 3

Before installation, operation, maintenance or inspection of this product, thoroughly read through and
understand this manual and the associated manuals. Also, take care to handle the module properly and
safely.
This manual classifies the safety precautions into two categories:
Depending on the circumstances, procedures indicated by
It is important to follow all precautions for personal safety.
Store this manual in a safe place so that it can be taken out and read whenever necessary. Always forward it
to the end user.
1. DESIGN PRECAUTIONS
• Make sure to include the following safety circuits outside the PLC to ensure safe system operation even during
external power supply problems or PLC failure.
Otherwise, malfunctions may cause serious accidents.
1) Above all, the following components should be included: an emergency stop circuit, a protection circuit, an
interlock circuit for opposite movements (such as normal vs. reverse rotation), and an interlock circuit (to prevent
damage to the equipment at the upper and lower positioning limits).
2) Note that when the PLC CPU detects an error, such as a watchdog timer error, during self-diagnosis, all outputs
are turned off. Also, when an error that cannot be detected by the PLC CPU occurs in an input/output control
block, output control may be disabled.
External circuits and mechanisms should be designed to ensure safe machinery operation in such a case.
3) Note that when an error occurs in a relay, triac or transistor output device, the output could be held either on or
off.
For output signals that may lead to serious accidents, external circuits and mechanisms should be designed to
ensure safe machinery operation in such a case.
• Do not bundle the control line together with or lay it close to the main circuit or power line. As a guideline, lay the
control line at least 100mm (3.94") or more away from the main circuit or power line.
Noise may cause malfunctions.
• Ground the shield wire or shield of the shielded cable at one point on the PLC. However, do not ground them at the
same point as the high-voltage lines.
Noise may cause malfunctions.
• Install module so that excessive force will not be applied to the terminal blocks.
Failure to do so may result in wire damage/breakage or PLC failure.
Safety Precautions
(Read these precautions before using.)
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 cause severe injury.
Reference
Reference
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