docs: def select_delim(self, delim):
          '''Select desired delimeter
          
          Args:
              delim: The delimeter character you want.
          Returns:
              None
          Raises:
              RuntimeError: Delimeter too long.
          '''
          size = len(delim)
          if size > 20:
              raise RuntimeError('Delimeter too long')
          n1 = size/10
          n2 = size%10
          self.send('^SS'+chr(n1)+chr(n2))