const { connectSerialPort, ReadDataString } = require('rs232-tuanzin');

async function connectAndReadData() {
    const port = await connectSerialPort({ port: 'COM3',baudRate: 9600 }); // default parity = "", dataBits = 8, stopBits = 1, flowControl = false
    ReadDataString(port, (data) => {
        // Only returns data when there is a change
        console.log(data);
    })
}

// run
connectAndReadData()