Node-RED Siemens S7 PLC Connector

node-red-contrib-s7 is a Node-RED package designed to facilitate interaction with Siemens S7 series Programmable Logic Controllers (PLCs), including S7-300, S7-400, S7-1200, and S7-1500. Currently stable at version 3.1.3, this package offers a robust solution for integrating industrial automation into Node-RED flows. It provides specialized nodes—'S7 Endpoint' for connection management and variable configuration, and 'S7 In' for reading data—that are accessed directly through the Node-RED editor palette. Its key differentiators include a custom, simplified variable addressing scheme, support for various PLC data types (Boolean, Byte, Char, Int, DInt, Real, String), and flexible data retrieval modes (single variable, all variables per message, or all variables as a single object). The package is actively maintained, with updates typically aligned with Node-RED and Node.js LTS releases. Users should be aware of specific Node.js and Node-RED version requirements for compatibility. It originates from the ST-One project, emphasizing its industrial application focus.