fx3u-mcprotocol 1.0.0

MC Protocol Ethernet driver for Mitsubishi FX3 PLCs

fx3u-mcprotocol — Python MC Protocol Library for Mitsubishi FX3 PLCs

fx3u-mcprotocol is an open-source Python MC Protocol library for communicating with Mitsubishi FX3 series PLCs over Ethernet.

It allows Python applications to read PLC memory (D, M, X, Y, R devices) from Mitsubishi FX3 PLCs using
MC Protocol (ASCII mode) via Ethernet (TCP/IP).

The library is tested with FX3U + FX3U-ENET-ADP and is suitable for industrial automation, data acquisition, SCADA integration, and custom monitoring systems.

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Why fx3u-mcprotocol?

If you are searching for:

• MC Protocol Python library
• Mitsubishi FX3 PLC Python communication
• FX3U Ethernet Python driver
• Read Mitsubishi PLC data using Python

this library is designed exactly for that use case.

Unlike generic PLC libraries, fx3u-mcprotocol focuses specifically on FX3 PLCs and provides a simple, symbol-based API aligned with real industrial workflows.

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Features

• Python MC Protocol implementation for Mitsubishi FX3 PLCs
• Symbol-based addressing (D100, M8000, etc.)
• Read word devices (D, R, TN, TS, …)
• Read bit devices (M, X, Y)
• Multiple PLC connections in a single application
• CPU profile validation (FX3S / FX3G / FX3U / FX3GC)
• Modular architecture (transport, protocol, symbols, profiles)
• Pure Python (no external runtime dependencies)

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Installation

Install the library directly from PyPI:

pip install fx3u-mcprotocol

✅ Stable ASCII MC Protocol support (FX3 series)

⚠️ Binary MC Protocol support is experimental and may vary by firmware

Example

from fx3u_mcprotocol import FX3UClient

plc = FX3UClient(
    ip="192.168.4.4",
    port=5001,
    cpu="FX3U",
    mode="ascii",
)

plc.connect()

# Read PLC registers (D devices)
print(plc.readReg("D100"))
print(plc.readRegs("D100", 3))

# Read PLC bits (M devices)
print(plc.readBit("M0"))
print(plc.readBits("M8000", 1))  # RUN bit

plc.close()

This example demonstrates how to read Mitsubishi FX3 PLC memory using Python over Ethernet with MC Protocol.

Supported Mitsubishi PLCs

• Mitsubishi FX3U
• Mitsubishi FX3G
• Mitsubishi FX3S
• Mitsubishi FX3GC

Note

• The library is tested on FX3U + FX3U-ENET-ADP. Other FX3 models are supported based on documented memory ranges.

Multiple PLC Example (Polling)

from fx3u_mcprotocol import FX3UClient

plcs = {
    "PLC_1": "192.168.4.2",
    "PLC_2": "192.168.4.3",
}

clients = {}

for name, ip in plcs.items():
    plc = FX3UClient(ip=ip, cpu="FX3U", mode="ascii", read_only=True)
    plc.connect()
    clients[name] = plc

for name, plc in clients.items():
    print(name, plc.readRegs("D100", 3))

This approach is commonly used for:

• Data logging

• Multi-machine monitoring

• SCADA gateway development

Architecture Overview

The library is intentionally modular:

• transport — TCP/IP socket communication

• protocol — MC Protocol frame encoding/decoding

• symbols — PLC symbol parsing (D100, M8000)

• profiles — PLC CPU memory range validation

• client — High-level user API

This design allows easy extension and future support for additional PLC families or protocols.

Legal Notice

• This is an independent, open-source implementation based on publicly available protocol documentation.

• This project is not affiliated with, endorsed by, or sponsored by Mitsubishi Electric.

License

• This project is licensed under the MIT License.
• See the LICENSE file for details.

Author

Piyush Ghumelia

Industrial Automation & Python Developer

PyPI: https://pypi.org/project/fx3u-mcprotocol/