Development of demarcation load switch controller

The hardware and software design of demarcation load switch controller installed in 10KV distribution grid are introduced. This device employs the MCF52259 to accomplish microprocessor protection and employs the LAN9313 to achieve communication over the Ethernet. Connections between MCF52259 and circuits in other functional modules are also detailed. In addition, Main system program and interrupt service routine are introduced in the paper. The device will accomplish fault diagnosis and remove the fault promptly to improve power supply reliability.