Function read_ring_indicator 

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

Reads the RI (Ring Indicator) control signal state

Reads the current state of the RI signal line. This signal indicates that an incoming call 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 RI signal state (true for high, false for low), or an Error if it failed.

Example

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

JavaScript Equivalent

import { SerialPort } from "tauri-plugin-serialplugin-api";;
 
const port = new SerialPort({ path: "COM1" });
await port.open();
const riState = await port.readRingIndicator();
console.log("Ring indicator is:", riState ? "active" : "inactive");