nodejs nrf24

function transmitCommand(identifier,command) {
  console.log('In transmit command');
  console.log('identifier: ' + numHex(identifier));
  console.log('command: ' + command);     
  
  var txAddress = parseInt("0xE8E8F0"+numHex(identifier)+"E2", 16);
  tx = radio.openPipe('tx', txAddress,{autoAck:true}); 
  
  tx.on('ready', function () {   
       console.log("Radio is ready:");
       //radio.printDetails();
       console.log("Transmitting command:" + command + "for identifier"+ identifier);
       var b = new Buffer([command, identifier]);       
       try {
           var err = tx.write(b);
           throw err;
       } catch (err) {
            console.log(err);
       } finally {
         //rx.close(); 
         //tx.close();  
       }
       //no error:
       // if turn on command, add to turnedOnNodes
       if (command == Command.TurnOn) {
           addNode(numHex(identifier),true);    
       } else if (command == Command.TurnOff) {
           addNode(numHex(identifier),false);
       }
    });
   tx.on('error', function (error) {
    	console.log("an error has happened trying to transmit to node."+error);
    });
}