RModBus - free implementation of ModBus protocol in pure Ruby
Ruby

README.md

RModBus Build Status Gem Version

RModBus - free implementation of ModBus protocol in pure Ruby.

Features

  • Ruby 2.2, 2.3 and JRuby (without serial ModBus RTU)
  • TCP, RTU, RTU over TCP protocols
  • Client(master) and server(slave)
  • 16, 32 -bit and float registers

Support functions

  • Read Coils (0x01)
  • Read Discrete Inputs (0x02)
  • Read Holding Registers (0x03)
  • Read Input Registers (0x04)
  • Write Single Coil (0x05)
  • Write Single Register (0x06)
  • Write Multiple Coils (0x0F)
  • Write Multiple registers (0x10)
  • Mask Write register (0x16)

Installation

Download and install RModBus with the following:

gem install rmodbus

Or if you are using bundler, add to your Gemfile:

gem 'rmodbus'

If you want to use ModBus over serial, you will also need to install the 'serialport' gem. If you are using bundler, add to your Gemfile:

gem 'serialport'

If you want to use ModBus::TCPServer or ModBus::RTUViaTCPServer and are using Ruby >= 2.2, you will also need to install the 'gserver' gem. If you are using bundler, add to your Gemfile:

gem 'gserver'

Please note that GServer is deprecated, and I'm looking for a better solution. Contributions are welcome!

Example

    require 'rmodbus'

    ModBus::TCPClient.new('127.0.0.1', 8502) do |cl|
      cl.with_slave(1) do |slave|
        # Read a single holding register at address 16
        slave.holding_registers[16]

        # Write a single holding register at address 16
        slave.holding_registers[16] = 123

        # Read holding registers 16 through 20
        slave.holding_registers[16..20]

        # Write holding registers 16 through 20 with some values
        slave.holding_registers[16..20] = [1, 2, 3, 4, 5]
      end
    end

Versioning

This project will follow http://semver.org/

Given a version number MAJOR.MINOR.PATCH, increment the:

MAJOR version when you make incompatible API changes,
MINOR version when you add functionality in a backwards-compatible manner, and
PATCH version when you make backwards-compatible bug fixes.

Contributing

See CONTRIBUTING.

Reference

RModBus on GitHub: http://github.com/rmodbus/rmodbus

Documentation: http://www.rubydoc.info/github/rmodbus/rmodbus

ModBus specifications: http://www.modbus.org/specs.php

License

GPL v3

Credits

Aleksey Timin - original author