13. Diagnostics - Mitsubishi FX3U-20SSC-H User Manual

FX -20SSC-H Positioning Block User's Manual
3U

13. Diagnostics

When a fault occurs, check the power supply voltage, the PLC main unit and I/O devices for loose
terminal screws, and examine the connectors for a defective contact.
STARTUP AND MAINTENANCE
PRECAUTIONS
• Do not touch any terminal while the PLC's power is on. Doing so may cause electric shock or malfunctions.
• Before cleaning or retightening terminals, externally cut off all phases of the power supply. Failure to do so may cause electric shock.
• Before modifying or disrupting the program in operation or running the PLC, carefully read through this manual and the associated
manuals and ensure the safety of the operation. An operation error may damage the machinery or cause accidents.
• When verifying the Zero-return/JOG operation and positioning data, thoroughly read this manual to ensure safe system operation.
Failure to do so may cause an operation failure that leads to a serious accident or that causes damage to the machinery.
STARTUP AND MAINTENANCE
PRECAUTIONS
• Do not disassemble or modify the PLC. Doing so may cause fire, equipment failures, or malfunctions. For repair, contact your local
Mitsubishi Electric distributor.
• Turn off the power to the PLC before connecting or disconnecting any extension cable. Failure to do so may cause equipment failures
or malfunctions.
• Turn off the power to the PLC before attaching or detaching the following devices. Failure to do so may cause equipment failures or
malfunctions.
- Display module, peripheral devices, expansion boards, and special adapters
- Terminal blocks and I/O extension units/blocks
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