# NModbus/NModbus

NModbus is a C# implementation of the Modbus protocol.

Repository: https://github.com/NModbus/NModbus
Canonical: https://ross.abutalabs.com/products/nmodbus
Language: C#
License: MIT
License Family: permissive
Last push: 2026-06-30T15:59:15+00:00

## Health v2 (maintenance only)
Score: 73/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 90, release rhythm 35, longevity 100
- inputs: {"age_days": 3425, "days_push": 64, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1084, forks 318 (observed 2026-08-28T04:03:31.434762+00:00)

## What it is
NModbus is a C# (.NET) library implementing the Modbus protocol, supporting serial ASCII, serial RTU, TCP, and UDP transports. It enables communication with Modbus slave devices and hosting multiple slave devices on the same transport.

## Use cases
- communicate with PLCs and Modbus slave devices from C#
- read registers from a Modbus TCP device
- implement a Modbus RTU master over serial port
- simulate multiple Modbus slave devices on one transport
- poll industrial sensors over Modbus UDP
- add custom Modbus function code handlers to a slave device

## When to choose
- you need a mature MIT-licensed Modbus implementation for .NET
- you need both master and slave support across TCP, UDP, and serial transports
- you need to host multiple slave devices on a single physical connection

## When to avoid
- you need Modbus support outside the .NET ecosystem
- you need active ongoing development with frequent updates
- you need higher-level industrial protocol stacks like OPC UA

## Facets
- artifact type: library
- maturity: maintenance
- function: networking, sdk, developer-tools
- domain: iot, embedded-systems, hardware
- platform: cross-platform, dotnet
- tags: modbus, industrial-automation, serial-communication, rtu, modbus-tcp, scada, automation

## Member repositories
- NModbus/NModbus (main) score 73

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:31.434762+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:49:59.562405+00:00, confidence not recorded.
  - readme: https://github.com/NModbus/NModbus (fetched 2026-08-28T04:03:31.434762+00:00, sha efa1a5b321aa)
- Data as of 2026-08-30T08:39:29.467469+00:00.