Try this one. It just replaces the loop code you used for reading the values using serial and all the xSend routine.
while(Serial.available > 0){ // Serial byte(s) available?
if(Serial.read() == 13){ // Yes, Is it 13
xSend(x22D, s22D); // Yes, so send reply
xSend(x139, s139);
xSend(x2C1, s2C1);
}
}