import processing.net.*; 
Client myClient; 
String inString;
 
void setup() { 
  size (300, 150);
  myClient = new Client(this, "192.168.1.101", 23); 
  String mdp = "1234";
  myClient.write("\r\n" + mdp + "\r\n");
} 
 
void draw() { 
  if (myClient.available() > 0) { 
    background(0); 
    inString = myClient.readString(); 
    println(inString); 
  }
} 
 
void keyPressed() {
  myClient.write("012\r\n"); // Envoi la commande lecture
}

Spécifications pour Telnet et RS232