Len Substaions Systems is an instrument that connects one substation to another substation to produce intertripping. This is a protection function to prevent electrical substations from being charged abnormally. The host and substation next to it exchange status via the LBD panel. They use optical fiber as a TCP / IP communication and ethernet media interface as a communication protocol. Every time a problem occurs, such as a short circuit, HOst LBD will send a trip command (status) to the substation next to it. When this status is received, the substation next to it will also travel.