gistfile1.js

var stream = require('stream');
 
var timer = new stream.Readable({
   read: function() {
      var self = this;
 
      console.log('called');
      setTimeout(function() {
          if(!timer.isPaused()){
           self.push('ping\n');
           console.log('pushed');
          }
      }, 100);
   }
});
 
timer.pipe(process.stdout);

timer.on('data', function(){
  console.log('data', arguments)
})
 
timer.on('readable', function(){
  console.log('readable', arguments)
})

timer.on('close', function(){
  console.log('close', arguments)
})

timer.on('error', function(){
  console.log('error', arguments)
})

timer.on('end', function(){
  console.log('end', arguments)
})

setTimeout(function() {
  timer.unpipe(process.stdout);
  timer.pause()
}, 500);

output.txt

$ node streamtest.js
called
ping
data { '0': <Buffer 70 69 6e 67 0a> }
called
pushed
ping
data { '0': <Buffer 70 69 6e 67 0a> }
called
pushed
ping
data { '0': <Buffer 70 69 6e 67 0a> }
called
pushed
ping
data { '0': <Buffer 70 69 6e 67 0a> }
called
pushed