code: public static String decodeTPCI(int tpci, KNXAddress dst)
  	{
  		final int ctrl = tpci & 0xff;
  		if ((ctrl & 0xFC) == 0) {
  			if (dst == null)
  				return "T-broadcast/group/ind";
  			if (dst.getRawAddress() == 0)
  				return "T-broadcast";
  			if (dst instanceof GroupAddress)
  				return "T-group";
  			return "T-individual";
  		}
  		if ((ctrl & 0xC0) == 0x40)
  			return "T-connected seq " + (ctrl >> 2 & 0xF);
  		if (ctrl == T_CONNECT)
  			return "T-connect";
  		if (ctrl == T_DISCONNECT)
  			return "T-disconnect";
  		if ((ctrl & 0xC3) == T_ACK)
  			return "T-ack seq " + (ctrl >> 2 & 0xF);
  		if ((ctrl & 0xC3) == T_NAK)
  			return "T-nak seq " + (ctrl >> 2 & 0xF);
  		return "unknown TPCI";
  	}
docs: Decodes a transport layer protocol control information into a textual
  representation.
  <p>
  
  @param tpci transport layer protocol control information
  @param dst KNX destination address belonging to the tpci, might be
  <code>null</code>
  @return textual representation of TPCI