title: How to using asynchronous events in restify
body: <p>I have a simple restify webservice that calls a function writing an command to a serial port</p>
  
  <pre><code>var restify = require('restify')
  var com = require("serialport");
  
  server.get('/scaleGetWeight/', getScaleWeight);
  server.head('/scaleGetWeight/', getScaleWeight);
  
  function getScaleWeight(req, res, next) {
      serialPort.write("S\r\n");
      res.send(?);
  }
  </code></pre>
  
  <p>the serial port returns the request in an event</p>
  
  <pre><code>serialPort.on('data', function(data) {
    console.log(data);;
  });
  </code></pre>
  
  <p>What is the right way to get the result back to the client?</p>