[][src]Crate tokio_modbus

A pure Rust Modbus library based on tokio.

Modbus is based on a master/slave model. To avoid confusions with the tokio terminology the master is called client and the slave is called server in this library.

Features

  • pure Rust library
  • async (non-blocking)
  • sync (blocking)
  • Modbus TCP
  • Modbus RTU
  • Client & Server
  • Open Source (MIT/Apache-2.0)

Installation

Add this to your Cargo.toml:

[dependencies]
tokio-modbus = "*"

If you like to use Modbus TCP only:

[dependencies]
tokio-modbus = { version = "*", default-features = false, features = ["tcp"] }

If you like to use Modbus RTU only:

[dependencies]
tokio-modbus = { version = "*", default-features = false, features = ["rtu"] }

Examples

TCP client

use tokio_core::reactor::Core;
use futures::Future;
use tokio_modbus::prelude::*;

pub fn main() {
    let mut core = Core::new().unwrap();
    let handle = core.handle();
    let socket_addr = "192.168.0.222:502".parse().unwrap();

    let task = tcp::connect(&handle, socket_addr).and_then(|ctx| {
        ctx
            .read_input_registers(0x1000, 7)
            .and_then(move |data| {
                println!("Response is '{:?}'", data);
                Ok(())
            })
    });
    core.run(task).unwrap();
}

Sync TCP client

use tokio_modbus::prelude::*;

pub fn main() {
    let socket_addr = "192.168.0.222:502".parse().unwrap();
    let mut client = client::sync::tcp::connect(socket_addr).unwrap();
    let data = client.read_input_registers(0x1000, 7).unwrap();
    println!("Response is '{:?}'", data);
}

RTU client

use tokio_core::reactor::Core;
use futures::Future;
use tokio_serial::{Serial, SerialPortSettings};

 use tokio_modbus::prelude::*;

pub fn main() {
    let mut core = Core::new().unwrap();
    let handle = core.handle();
    let tty_path = "/dev/ttyUSB0";
    let slave = Slave(0x17);

    let mut settings = SerialPortSettings::default();
    settings.baud_rate = 19200;
    let port = Serial::from_path_with_handle(tty_path, &settings, &handle.new_tokio_handle()).unwrap();

    let task = rtu::connect_slave(&handle, port, slave).and_then(|ctx| {
        println!("Reading a sensor value");
        ctx
            .read_holding_registers(0x082B, 2)
            .and_then(move |rsp| {
                println!("Sensor value is: {:?}", rsp);
                Ok(())
            })
    });

    core.run(task).unwrap();
}

More examples can be found in the examples folder.

Protocol-Specification

Modules

client
prelude
server
slave