Crate r4dcb08_lib 

A library for controlling the R413D08 8-channel relay module via Modbus.

This crate provides two main ways to interact with the R413D08 relay module:

1. High-Level, Safe Clients: Stateful, thread-safe clients that are easy to share and use in concurrent applications. This is the recommended approach for most users. See tokio_sync_safe_client::SafeClient (blocking) and tokio_async_safe_client::SafeClient (async).

2. Low-Level, Stateless Functions: A set of stateless functions that directly map to the device’s Modbus commands. This API offers maximum flexibility but requires manual management of the Modbus context. See the tokio_sync and tokio_async modules.

Key Features

• Protocol Implementation: Complete implementation of the R413D08 Modbus protocol.
• Stateful, Thread-Safe Clients: For easy and safe concurrent use.
• Stateless, Low-Level Functions: For maximum flexibility and control.
• Synchronous and Asynchronous APIs: Both blocking and async/await APIs are available.
• Strongly-Typed API: Utilizes Rust’s type system for protocol correctness (e.g., Port, Address, PortState).

Cargo Features

This crate uses feature flags to enable different functionalities and to select the desired tokio-modbus backend.

For library users, it is recommended to disable the default features and enable only the ones you need. For example, in your Cargo.toml:

[dependencies.R4DCB08]
version = "0.3"
default-features = false
features = ["tokio-tcp-sync", "safe-client-sync"]

Available Features

• tokio-rtu-sync: Enables the synchronous (blocking) RTU backend.
• tokio-tcp-sync: Enables the synchronous (blocking) TCP backend.
• tokio-rtu: Enables the asynchronous (async) RTU backend.
• tokio-tcp: Enables the asynchronous (async) TCP backend.
• safe-client-sync: Enables the high-level, thread-safe, synchronous tokio_sync_safe_client::SafeClient. Requires either tokio-rtu-sync or tokio-tcp-sync.
• safe-client-async: Enables the high-level, thread-safe, asynchronous tokio_async_safe_client::SafeClient. Requires either tokio-rtu or tokio-tcp.
• serde: Enables serde support for the protocol types.
• bin-dependencies: Enables all dependencies required for the R4DCB08 binary. This is not intended for library users.

The default feature enables bin-dependencies.

Quick Start

This example shows how to use the recommended high-level, synchronous SafeClient.

use r4dcb08_lib::{
    protocol::Address,
    tokio_sync_safe_client::SafeClient,
};
use tokio_modbus::client::sync::tcp;
use tokio_modbus::Slave;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Connect to the device and create a stateful, safe client
    let socket_addr = "192.168.1.100:502".parse()?;
    let ctx = tcp::connect_slave(socket_addr, Slave(*Address::default()))?;
    let mut client = SafeClient::new(ctx);

    // Use the client to interact with the device
    let temperatures = client.read_temperatures()?;

    println!("Successfully read temperatures. Current values: {}", temperatures);

    Ok(())
}

For more details, see the documentation for the specific client you wish to use.

Modules

protocol

Defines data structures, constants, and protocol logic for interacting with an 8-Channel temperature module using the Modbus RTU protocol, based on the protocol specification document.

tokio_asynctokio-rtu or tokio-tcp

Asynchronous tokio-modbus client for the R4DCB08 temperature module.

tokio_async_safe_clientsafe-client-async and (tokio-rtu or tokio-tcp)

Asynchronous tokio-modbus client for the R4DCB08 temperature module.

tokio_commontokio-rtu-sync or tokio-tcp-sync or tokio-rtu or tokio-tcp

This module provides common data structures and error types for the tokio based clients.

tokio_synctokio-rtu-sync or tokio-tcp-sync

Synchronous tokio-modbus client for the R4DCB08 temperature module.

tokio_sync_safe_clientsafe-client-sync and (tokio-rtu-sync or tokio-tcp-sync)

Synchronous tokio-modbus client for the R4DCB08 temperature module.