communication working on server and client mode

README.md

@@ -1,4 +1,34 @@
 # mettler-toledo
 
-Test bench for communication with Mettler Toledo scale
+Test bench for communication with Mettler Toledo scale.
 specific model ICS 425
+
+## Modes
+Mettler Toledo scales have several ways to provide weight data. For our purpose the __Server__ or __Client__ options are the best match.
+Check manual section 3.6 Communication menu block (page 40)
+
+### Server mode
+The scale act as a server, on which is listening at specific IP address and port waiting for a comand.
+To request weight data the following command must be send to the scale controller
+````
+	 S\r\n
+````
+*\r\n means CR LF*
+
+
+#### Server mode configuration
+
+
+
+### Client mode
+The scale act as a client pushing continuos data to the server, configured as specific IP address and port
+
+Scale is contious sending data:
+````
+S S      0.000 kg
+
+S S      0.000 kg
+````
+
+#### Client mode configuration
+

client.go

@@ -0,0 +1,41 @@
+package main
+import (
+    "net"
+    "os"
+)
+
+func main() {
+    strEcho := "SI\r\n"
+    servAddr := "192.168.8.9:4305"
+    tcpAddr, err := net.ResolveTCPAddr("tcp", servAddr)
+    if err != nil {
+        println("ResolveTCPAddr failed:", err.Error())
+        os.Exit(1)
+    }
+
+    conn, err := net.DialTCP("tcp", nil, tcpAddr)
+    if err != nil {
+        println("Dial failed:", err.Error())
+        os.Exit(1)
+    }
+
+    _, err = conn.Write([]byte(strEcho))
+    if err != nil {
+        println("Write to server failed:", err.Error())
+        os.Exit(1)
+    }
+
+    println("write to server = ", strEcho)
+
+    reply := make([]byte, 1024)
+
+    _, err = conn.Read(reply)
+    if err != nil {
+        println("Write to server failed:", err.Error())
+        os.Exit(1)
+    }
+
+    println("reply from server=", string(reply))
+
+    conn.Close()
+}

server.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+    "fmt"
+  "net"
+  "os"
+)
+
+const (
+  CONN_HOST = "192.168.8.177"
+  CONN_PORT = "3333"
+  CONN_TYPE = "tcp"
+  CONN_URL  = CONN_HOST + ":" + CONN_PORT
+)
+
+func main() {
+  // Listen for incoming connections
+  l, err := net.Listen(CONN_TYPE, CONN_URL)
+
+  if err != nil {
+    fmt.Println("Error listening:", err.Error())
+    os.Exit(1)
+  }
+
+  // Close the listener when this application closes
+  defer l.Close()
+
+  fmt.Println("Listening on " + CONN_URL)
+  for {
+    // Listen for connections
+    conn, err := l.Accept()
+
+    if err != nil {
+      fmt.Println("Error accepting connection:", err.Error())
+      os.Exit(1)
+    }
+
+    go handleRequest(conn)
+  }
+}
+
+func handleRequest(conn net.Conn) {
+  // Buffer that holds incoming information
+  buf := make([]byte, 1024)
+
+  for {
+    len, err := conn.Read(buf)
+
+    if err != nil {
+      fmt.Println("Error reading:", err.Error())
+      break
+    }
+
+    s := string(buf[:len])
+
+    fmt.Println(s)
+  
+  }
+}