network between 3 xbee

Projects Networking, Protocols, and Devices
1

hello
i have to make an xbee network which contains three xbees one as a coordinator and two end devices.
the coordinator is connected to an arduino.
the two end devices don't have the same function.
so how the coordinator know witch one of the end devices will contact.
i think about the frame that i send with the arduino.
can i add something to indicate that this frame will be send to just one of those end devices ?

void setRemoteState(char value){
  Serial1.write(0x7E); // start byte
  Serial1.write((byte)0x0);
  Serial1.write(0x10);
  Serial1.write(0x17);
  Serial1.write((byte)0x0);
  // id of recipient or use 0xFFFF for broadcast
  Serial1.write((byte)00);
  Serial1.write((byte)00);
  Serial1.write((byte)00);
  Serial1.write((byte)00);
  Serial1.write((byte)00);
  Serial1.write((byte)00);
  Serial1.write(0xFF);
  Serial1.write(0xFF);
  // 16 bit of reciepent 
  Serial1.write(0xFF);
  Serial1.write(0xFE);  
  
   Serial1.write(0x02); 
   
   Serial1.write('D');
   Serial1.write('2');
   
   Serial1.write(value);
   
   long sum = 0x17 + 0xFF + 0xFF + 0xFF + 0xFE + 0x02 + 'D' + '2' + value;
   Serial1.write(0xFF - ( sum & 0xFF) );
   Serial1.println(sum,HEX);
}