#!/usr/bin/env python # -*- coding: utf-8 -*- """ Modbus TestKit: Implementation of Modbus protocol in python (C)2009 - Luc Jean - luc.jean@gmail.com (C)2009 - Apidev - http://www.apidev.fr This is distributed under GNU LGPL license, see license.txt """ from __future__ import print_function import sys import threading import logging import socket import select from modbus_tk import LOGGER PY2 = sys.version_info[0] == 2 PY3 = sys.version_info[0] == 3 def threadsafe_function(fcn): """decorator making sure that the decorated function is thread safe""" lock = threading.RLock() def new(*args, **kwargs): """Lock and call the decorated function Unless kwargs['threadsafe'] == False """ threadsafe = kwargs.pop('threadsafe', True) if threadsafe: lock.acquire() try: ret = fcn(*args, **kwargs) except Exception as excpt: raise excpt finally: if threadsafe: lock.release() return ret return new def flush_socket(socks, lim=0): """remove the data present on the socket""" input_socks = [socks] cnt = 0 while True: i_socks = select.select(input_socks, input_socks, input_socks, 0.0)[0] if len(i_socks) == 0: break for sock in i_socks: sock.recv(1024) if lim > 0: cnt += 1 if cnt >= lim: #avoid infinite loop due to loss of connection raise Exception("flush_socket: maximum number of iterations reached") def get_log_buffer(prefix, buff): """Format binary data into a string for debug purpose""" log = prefix for i in buff: log += str(ord(i) if PY2 else i) + "-" return log[:-1] class ConsoleHandler(logging.Handler): """This class is a logger handler. It prints on the console""" def __init__(self): """Constructor""" logging.Handler.__init__(self) def emit(self, record): """format and print the record on the console""" print(self.format(record)) class LogitHandler(logging.Handler): """This class is a logger handler. It send to a udp socket""" def __init__(self, dest): """Constructor""" logging.Handler.__init__(self) self._dest = dest self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) def emit(self, record): """format and send the record over udp""" data = self.format(record) + "\r\n" if PY3: data = to_data(data) self._sock.sendto(data, self._dest) class DummyHandler(logging.Handler): """This class is a logger handler. It doesn't do anything""" def __init__(self): """Constructor""" super(DummyHandler, self).__init__() def emit(self, record): """do nothing with the given record""" pass def create_logger(name="dummy", level=logging.DEBUG, record_format=None): """Create a logger according to the given settings""" if record_format is None: record_format = "%(asctime)s\t%(levelname)s\t%(module)s.%(funcName)s\t%(threadName)s\t%(message)s" logger = logging.getLogger("modbus_tk") logger.setLevel(level) formatter = logging.Formatter(record_format) if name == "udp": log_handler = LogitHandler(("127.0.0.1", 1975)) elif name == "console": log_handler = ConsoleHandler() elif name == "dummy": log_handler = DummyHandler() else: raise Exception("Unknown handler %s" % name) log_handler.setFormatter(formatter) logger.addHandler(log_handler) return logger def swap_bytes(word_val): """swap lsb and msb of a word""" msb = (word_val >> 8) & 0xFF lsb = word_val & 0xFF return (lsb << 8) + msb def calculate_crc(data): """Calculate the CRC16 of a datagram""" CRC16table = ( 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 ) crc = 0xFFFF if PY2: for c in data: crc = (crc >> 8) ^ CRC16table[(ord(c) ^ crc) & 0xFF] else: for c in data: crc = (crc >> 8) ^ CRC16table[((c) ^ crc) & 0xFF] return swap_bytes(crc) def calculate_rtu_inter_char(baudrate): """calculates the interchar delay from the baudrate""" if baudrate <= 19200: return 11.0 / baudrate else: return 0.0005 class WorkerThread(object): """ A thread which is running an almost-ever loop It can be stopped by calling the stop function """ def __init__(self, main_fct, args=(), init_fct=None, exit_fct=None): """Constructor""" self._fcts = [init_fct, main_fct, exit_fct] self._args = args self._thread = threading.Thread(target=WorkerThread._run, args=(self,)) self._go = threading.Event() def start(self): """Start the thread""" self._go.set() self._thread.start() def stop(self): """stop the thread""" if self._thread.isAlive(): self._go.clear() self._thread.join() def _run(self): """main function of the thread execute _main_fct until stop is called""" #pylint: disable=broad-except try: if self._fcts[0]: self._fcts[0](*self._args) while self._go.isSet(): self._fcts[1](*self._args) except Exception as excpt: LOGGER.error("error: %s", str(excpt)) finally: if self._fcts[2]: self._fcts[2](*self._args) def to_data(string_data): if PY2: return string_data else: return bytearray(string_data, 'ascii')