OpenOPC.py 文件源码

def __init__(self, opc_class=None, client_name=None):
      """Instantiate OPC automation class"""

      self.callback_queue = Queue.Queue()

      pythoncom.CoInitialize()

      if opc_class == None:
         if os.environ.has_key('OPC_CLASS'):
            opc_class = os.environ['OPC_CLASS']
         else:
            opc_class = OPC_CLASS

      opc_class_list = opc_class.split(';')

      for i,c in enumerate(opc_class_list):
         try:
            self._opc = win32com.client.gencache.EnsureDispatch(c, 0)
            self.opc_class = c
            break
         except pythoncom.com_error, err:
            if i == len(opc_class_list)-1:
               error_msg = 'Dispatch: %s' % self._get_error_str(err)
               raise OPCError, error_msg


      self._event = win32event.CreateEvent(None,0,0,None)

      self.opc_server = None
      self.opc_host = '128.100.1.21'
      self.client_name = client_name
      self._groups = {}
      self._group_tags = {}
      self._group_valid_tags = {}
      self._group_server_handles = {}
      self._group_handles_tag = {}
      self._group_hooks = {}
      self._open_serv = None
      self._open_self = None
      self._open_host = None
      self._open_port = None
      self._open_guid = None
      self._prev_serv_time = None
      self._tx_id = 0
      self.trace = None
      self.cpu = None