Socket Programming Question?

Projects Programming
3

I wanna get "120" in serial monitor not 1 then 2 then 0...

Then, you need to read and print the data correctly.

Is it and Arduino Coding problem

Yes.

if (client.available()) {  
char c = client.read(); 
Serial.print("Value received:  ");  
Serial.println(c);

You are sending "120" (that's '1', '2', and '0'). Then, you see if there is at least one character available to read, and, if so, you read exactly one character. That would be the '1' on one pass, then the '2' on another pass, and the '0' on another pass.

You need to send packets, with start and end markers, from the C# application, like "<120>". Then, use code like this to read it:

#define SOP '<'
#define EOP '>'

bool started = false;
bool ended = false;

char inData[80];
byte index;

void setup()
{
   Serial.begin(57600);
   // Other stuff...
}

void loop()
{
  // Read all serial data available, as fast as possible
  while(Serial.available() > 0)
  {
    char inChar = Serial.read();
    if(inChar == SOP)
    {
       index = 0;
       inData[index] = '\0';
       started = true;
       ended = false;
    }
    else if(inChar == EOP)
    {
       ended = true;
       break;
    }
    else
    {
      if(index < 79)
      {
        inData[index] = inChar;
        index++;
        inData[index] = '\0';
      }
    }
  }

  // We are here either because all pending serial
  // data has been read OR because an end of
  // packet marker arrived. Which is it?
  if(started && ended)
  {
    // The end of packet marker arrived. Process the packet

    // Reset for the next packet
    started = false;
    ended = false;
    index = 0;
    inData[index] = '\0';
  }
}