Node-RED KV Host Link Nodes for KEYENCE PLCs

Node-RED nodes for KEYENCE KV series PLC communication over KV Host Link (Upper Link), using the same high-level read/write model as the existing Python and .NET libraries.

Quick start

1. Install the package into your Node-RED user directory and restart Node-RED.
2. Add one kvhostlink-connection config node and set host, port, and transport.
3. Import kvhostlink-basic-read-write.json for the first smoke test.
4. When scalar read/write works, move to kvhostlink-typed-read-write.json and kvhostlink-array-read-write.json.
5. Use kvhostlink-device-matrix.json only after the basics are stable.

Release information

• package name: @fa_yoshinobu/node-red-contrib-plc-comm-kvhostlink
• package version: 0.2.0
• npm package: https://www.npmjs.com/package/@fa_yoshinobu/node-red-contrib-plc-comm-kvhostlink
• Node-RED requirement: >=3.0.0
• Node.js requirement: >=18
• changelog: https://github.com/fa-yoshinobu/node-red-contrib-plc-comm-kvhostlink/blob/main/CHANGELOG.md

Install from npm:

cd ~/.node-red
npm install @fa_yoshinobu/node-red-contrib-plc-comm-kvhostlink

Install from this repository:

cd ~/.node-red
npm install /path/to/node-red-contrib-plc-comm-kvhostlink

Documentation

• User Guide
• Example Flows
• Future Device Support
• Maintainer Notes
• Validation Reports Directory
• Documentation Index

Current scope

• TCP and UDP transport
• Reusable kvhostlink-connection config node
• kvhostlink-read powered by the high-level helper API
• kvhostlink-write powered by the high-level helper API
• high-level scalar, signed, dword, long, float, bit-in-word, and ,count forms
• matrix-style debug flow with JSONL result logging
• beginner-oriented sample flows for scalar, typed, and array patterns
• local tests for protocol parsing and high-level helper behavior
• local Node-RED runtime smoke test confirmed the basic flow loads and starts successfully

Supported high-level address forms include:

• DM100
• DM110:S
• DM120:D
• DM130:L
• DM140:F
• DM150.3
• DM160,4
• R200,4
• T10:D
• C10:D

Validated PLC model:

• KV-7500

Supported devices

Supported bit devices:

• R, B, MR, LR, CR, VB
• X, Y, M, L

Supported word devices:

• DM, EM, FM, ZF, W, TM, Z
• TC, TS, CC, CS
• CM, VM
• D, E, F

Supported high-level timer and counter scalar forms:

• Tn:D
• Cn:D

Example flows

• kvhostlink-basic-read-write.json First-step scalar read/write flow.
• kvhostlink-typed-read-write.json Signed, dword, long, float, and bit-in-word examples.
• kvhostlink-array-read-write.json ,count read/write examples for words and bits.
• kvhostlink-device-matrix.json High-level matrix-style verification flow. Completed results are appended to logs/kvhostlink-device-matrix-<session>.jsonl under your Node-RED user directory.

Known limitations

• AT remains pending support and is tracked in TODO.md.
• The package now has beginner flows, but the validation coverage and example breadth are still narrower than node-red-contrib-plc-comm-slmp.