Function read_carrier_detect 

pub fn read_carrier_detect<R: Runtime>(
    _app: AppHandle<R>,
    serial: State<'_, SerialPort<R>>,
    path: String,
) -> Result<bool, Error>

Reads the CD (Carrier Detect) control signal state

Reads the current state of the CD signal line. This signal indicates whether a carrier signal is being received (commonly used with modems).

Arguments

• _app - The Tauri app handle
• serial - The serial port state
• path - The path to the serial port (e.g., “COM1”, “/dev/ttyUSB0”)

Returns

The CD signal state (true for high, false for low), or an Error if it failed.

Example

use tauri_plugin_serialplugin::commands::read_carrier_detect;
use tauri::{AppHandle, State};
 
#[tauri::command]
async fn check_carrier(
    app: AppHandle<tauri::Wry>,
    serial: State<'_, tauri_plugin_serialplugin::desktop_api::SerialPort<tauri::Wry>>
) -> Result<(), String> {
    let cd_state = read_carrier_detect(app, serial, "COM1".to_string())
        .map_err(|e| e.to_string())?;
    println!("Carrier detect is: {}", if cd_state { "active" } else { "inactive" });
    Ok(())
}

JavaScript Equivalent

import { SerialPort } from "tauri-plugin-serialplugin-api";;
 
const port = new SerialPort({ path: "COM1" });
await port.open();
const cdState = await port.readCarrierDetect();
console.log("Carrier detect is:", cdState ? "active" : "inactive");