while (Serial.available()<9) {} // Wait 'till there are 9 Bytes waiting
for(int n=0; n<9; n++)
RFin_bytes[n] = Serial.read(); // Then: Get them.

//zoomkat 9-9-10 simple delimited ',' string parce
//from serial port input (via serial monitor)
//and print result out serial port
// CR/LF could also be a delimiter

String readString;

void setup() {
Serial.begin(9600);
}

void loop() {

    //expect a string like wer,qwe rty,123 456,hyre kjhg,
    //or like hello world,who are you?,bye!,
    while (Serial.available()) {
    delay(1);  //small delay to allow input buffer to fill
    char c = Serial.read();  //gets one byte from serial buffer
    if (c == ',') {break;}  //breaks out of capture loop to print readstring
    readString += c; //makes the string readString
    }

  if (readString.length() >0) {
  Serial.println(readString); //prints string to serial port out

  //do stuff here

  readString=""; //clears variable for new input
  }

}