METHOD AND APPARATUS FOR TRANSMISSION OF DATA OVER POWER LINES

摘要

A method of coordinating the transmission of polling messages from a low voltage distribution substation and the responses from a plurality of electricity meters is provided. The transmissions and responses are communicated over the low voltage distribution network. Precise phase of the data bit timing of transmitted polling messages from the substation is preserved between transmissions and the response from electricity meters maintains the phase of the data bit timing of the messages from the substation in its own transmissions. A further feature of the invention is to operate a mains metering system so as to avoid interference between polled data collection systems operating from each of a plurality of interconnected substations. This is achieved by operating each of the polled data collection systems on a separate frequency. By operating a plurality of polled data collection systems each on a separate frequency the information carrying capacity of a power distribution network data transmission system is increased.