def METHOD_NAME(self):
    port_dict = {}
    while True:
        for port_num in range(self.port_start, (self.port_end + 1)):
            presence = self.get_presence(port_num)
            if(presence and self._global_port_pres_dict[port_num] == '0'):
                self._global_port_pres_dict[port_num] = '1'
                port_dict[port_num] = '1'
            elif(not presence and
                 self._global_port_pres_dict[port_num] == '1'):
                self._global_port_pres_dict[port_num] = '0'
                port_dict[port_num] = '0'
            if(len(port_dict) > 0):
                return True, port_dict
        time.sleep(0.5)