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S7 Communication Suite

Node-RED TypeScript Siemens IIoT
Table of Contents

The Problem
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Siemens S7 PLCs are everywhere in industrial automation — but connecting them to Node-RED has always been a trade-off. Pure JavaScript libraries work without native compilation but lack advanced features. Native Snap7 bindings offer full protocol support but are harder to install. And during development, you often don’t have a real PLC available at all.

The Solution
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A Node-RED package for Siemens S7 communication that lets you choose your backend — pure JS, native Snap7, or a built-in simulator — without changing your flows. Written in TypeScript for type safety and reliability.

GitHub Repository Thumbnail
blanpa/node-red-contrib-s7-suite

node-red-contrib-s7-suite

TypeScript
0
0

Three Backends, One API
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BackendCompilationBest For
nodes7None (pure JS)Easy install, basic S7 communication
node-snap7Native (Snap7)Advanced features, high performance
simNoneDevelopment and testing without hardware

Switch backends in the config node — your flows stay the same.

6 Nodes
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┌──────────┐     ┌──────────┐     ┌──────────┐
│ s7-read  │     │ s7-write │     │s7-trigger│
└────┬─────┘     └────┬─────┘     └────┬─────┘
     │                │                │
     └───────┬────────┴────────────────┘
             │
      ┌──────┴──────┐
      │  s7-config  │──→ PLC Connection
      └─────────────┘
         │       │
  ┌──────┴──┐ ┌──┴────────┐
  │s7-browse│ │ s7-control │
  └─────────┘ └────────────┘
  • s7-config — Manages PLC connections with backend selection and auto-reconnection
  • s7-read — Read multiple PLC addresses in a single request
  • s7-write — Write data to PLC memory with dynamic addressing
  • s7-trigger — Polling with edge detection and deadband filtering
  • s7-browse — Discover available data blocks with filtering
  • s7-control — CPU control operations (start, stop, cold start)

Supported Controllers
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S7-200, S7-300, S7-400, S7-1200, S7-1500, and LOGO!

Address Formats
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Three addressing styles — use whichever you’re comfortable with:

  • nodes7-style: DB1,REAL0
  • IEC-style: DB1.DBD0
  • Area-style: MW4, I0.1, QD8

Reliability
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  • Request queuing (max 100 concurrent)
  • Exponential backoff reconnection
  • Edge detection for boolean values
  • Deadband filtering to reduce noise

Quality
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  • Written in TypeScript with strict type checking
  • Jest test suite with 80% coverage threshold
  • Docker support for containerized deployment

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