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MELSEC SLMP — PLC setup

Configure the MELSEC PLC before connecting with any SLMP library. Each guide below covers one CPU or communication unit down to the parameter screens of the engineering tool, and ends with a first read using the libraries.

A power cycle is required after every parameter change. Pass the canonical PLC profile explicitly when opening a connection — the libraries do not infer it from the PLC.

Choose your model

These guides use TCP port 1025.

Built-in Ethernet (CPU module)

Model Configuration tool Canonical profile Setup guide
iQ-R GX Works3 melsec:iq-r iQ-R settings
iQ-F GX Works3 melsec:iq-f iQ-F settings
iQ-L GX Works3 melsec:iq-l iQ-L settings
MX-R GX Works3 melsec:mx-r MX-R settings
MX-F GX Works3 melsec:mx-f MX-F settings
QnUDV GX Works2 melsec:qnudv QnUDV settings
QnU GX Works2 melsec:qnu QnU settings
LCPU GX Works2 melsec:lcpu LCPU settings

Ethernet communication unit

Model Configuration tool Canonical profile Setup guide
RJ71EN71 GX Works3 melsec:iq-r:rj71en71 RJ71EN71 settings
QJ71E71-100 GX Works2 melsec:qcpu:qj71e71-100, melsec:qnu:qj71e71-100, or melsec:qnudv:qj71e71-100, matching the connected CPU generation QJ71E71-100 settings
LJ71E71-100 GX Works2 melsec:lcpu:lj71e71-100 LJ71E71-100 settings

Shared reference pages

These pages apply to every language implementation of SLMP.

Page Use it for
SLMP Troubleshooting & Codes Symptoms, end codes, and profile limit codes seen during live verification.
SLMP profile parameters Frame defaults, point limits, write policy, and device availability per profile.
SLMP device ranges Range rules, fixed ranges, and unsupported device families per profile.

Simulator connection notes for GX Simulator 3 are on the PLC setup guide overview.

After the PLC is configured

Start from the Getting started page for your language: .NET · Python · Rust · C++ (Arduino/PlatformIO) · Node-RED

To confirm the settings before writing any code, use PLC Scope and keep the first check read-only.