MELSEC QJ71E71-100 — PLC-side settings

MELSEC QJ71E71-100 — Ethernet communication unit for Q series.

What you need

Configuration tool: GX Works2
Network: Align IP address, subnet mask, and default gateway with your network environment.
After configuration: Power cycle the PLC to apply the new parameters.

Example values used in this guide

Parameter	Example value	Notes
IP address	`192.168.250.100`	Adapt to your network
TCP port	`1025`	MC Protocol / SLMP TCP
UDP port	`1035`	MC Protocol / SLMP UDP

PLC-side settings

Use the QJ71E71-100 when the Q series CPU does not have a built-in Ethernet port. The Ethernet unit profiles use 4E frames with Q/L compatibility; choose the canonical profile that matches the connected CPU generation.

Screen: Ethernet unit settings

Parameter	Setting
IP Address	`192.168.250.100` (example)
Subnet Mask	Match your network
Default Gateway	Match your network
Communication Data Code	Binary code communication
Write During RUN	Enabled (FTP and MC protocol)

Screen: Ethernet unit open settings

#	Protocol	Open Method	Local Port
1	TCP	MC Protocol	`1025`
2	UDP	MC Protocol	`1035`

Connecting with this library

Parameter	Value
Canonical profile	`melsec:qcpu:qj71e71-100`, `melsec:qnu:qj71e71-100`, or `melsec:qnudv:qj71e71-100`
Port (TCP)	`1025`
Port (UDP)	`1035`

Use melsec:qcpu:qj71e71-100 for QCPU, melsec:qnu:qj71e71-100 for QnU, and melsec:qnudv:qj71e71-100 for QnUDV.

Code example:

Python.NET (C#)

import asyncio

from slmp import SlmpConnectionOptions, SlmpTarget, open_and_connect, read_typed


async def main() -> None:
    options = SlmpConnectionOptions(
        host="192.168.250.100",
        port=1025,
        transport="tcp",
        plc_profile="melsec:qnudv:qj71e71-100",
        default_target=SlmpTarget(network=0, station=0xFF, module_io=0x03FF, multidrop=0),
    )
    async with await open_and_connect(options) as client:
        value = await read_typed(client, "D100", "U")
        print(f"D100={value}")


asyncio.run(main())

using PlcComm.Slmp;

var options = new SlmpConnectionOptions(
    "192.168.250.100", SlmpPlcProfile.QnUDVQj71E71100, 1025,
    SlmpTransportMode.Tcp, SlmpTargetAddress.OwnStation);
await using var client = await SlmpClientFactory.OpenAndConnectAsync(options);
var value = await client.ReadTypedAsync("D100", "U");
Console.WriteLine($"D100={value}");

The PLC-side settings on this page apply to every language. For Rust, C++ (Arduino/PlatformIO), and Node-RED, start from each library's Getting started.