OpenPort.js

var serialport = require('serialport');// include the library
   SerialPort = serialport.SerialPort; // make a local instance of it
   // get port name from the command line:
   portName = process.argv[2];
   
   var myPort = new SerialPort(portName, {
   baudRate: 9600,
   // look for return and newline at the end of each data packet:
   parser: serialport.parsers.readline("\r\n")
 });
 
 function showPortOpen() {
   console.log('port open. Data rate: ' + myPort.options.baudRate);
}
 
function saveLatestData(data) {
   console.log('data received: ' + data);
}
 
function showPortClose() {
   console.log('port closed.');
}
 
function showError(error) {
   console.log('Serial port error: ' + error);
}
 
myPort.on('open', showPortOpen);
myPort.on('data', saveLatestData);
myPort.on('close', showPortClose);
myPort.on('error', showError);