docs: def getPollingRate(self):
          """get data polling rate for sleepy end device"""
          print '%s call getPollingRate' % self.port
          sPollingRate = self.__sendCommand('pollperiod')[0]
          try:
              iPollingRate = int(sPollingRate)/1000
              fPollingRate = round(float(sPollingRate)/1000, 3)
              return fPollingRate if fPollingRate > iPollingRate else iPollingRate
          except Exception, e:
              ModuleHelper.WriteIntoDebugLogger("getPollingRate() Error: " + str(e))