RS485 using Serial.available() only scans one character

Projects Programming
6

Using the outlined examples I copied the code from Example_2. The problem remains the same

void loop() {

  unsigned int pos = 0;
  bool newData = false;

  while(Serial.available()>0 && newData == false) {

    Serial.print ("T "); // test if loop is triggered

    byte r = Serial.read();

    Serial.println(r); // test if loop is triggered


    if(r != '\n') {
      data[pos] = r;
      pos++;
    } else {
      Serial.println("N"); // test path is triggered
      data[pos] = '\0';
      newData = true;
      break;
    }

  }

  Serial.println("O"); // outside while

  if(newData) {
    Serial.println(data);
  }
}

The output constantly reads

T 120
T 120
...

Apparently Serial.available() becomes false after '120' is transmitted and no newline or other characters are detected over all the Serial.read() command that follows. Until the next telegram is transmitted ("x12").

Removing the debugging prints (T,O,N) does not affect the output, so it should not be a timing issue.