16 Input/Output Extension Blocks
210
FX3G Series Programmable Controllers
User's Manual - Hardware Edition
16. Input/Output Extension Blocks
DESIGN PRECAUTIONS
• Make sure to have the following safety circuits outside of the PLC to ensure safe system operation even during external power supply
problems or PLC failure.
Otherwise, malfunctions may cause serious accidents.
1) Most importantly, have the following: 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 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.
4) 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.
DESIGN PRECAUTIONS
• 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.
WIRING PRECAUTIONS
• Connect the AC power supply to the dedicated terminals specified in this manual.
If an AC power supply is connected to a DC input/output terminal or DC power supply terminal, the PLC will burn out.
• Make sure to cut off all phases of the power supply externally before attempting installation or wiring work.
Failure to do so may cause electric shock or damage to the product.
• Make sure to attach the terminal cover, offered as an accessory, before turning on the power or initiating operation after installation or
wiring work.
Failure to do so may cause electric shock.
WIRING PRECAUTIONS
• Connect the DC power supply to the dedicated terminals specified in this manual.
If an AC power supply is connected to a DC input/output terminal or DC power supply terminal, the PLC will burn out.
• Do not wire vacant terminals externally.
Doing so may damage the product.
• When drilling screw holes or wiring, make sure cutting or wire debris does not enter the ventilation slits.
Failure to do so may cause fire, equipment failures or malfunctions.
• Make sure to properly wire the FX
2N/FX3U Series extension equipment in accordance with the following precautions.
Failure to do so may cause electric shock, a short-circuit, wire breakage, or damage to the product.
- The disposal size of the cable end should follow the dimensions described in this manual.
- Tightening torque should be between 0.5 and 0.8 N•m.