Communication system, has slave user equipment comprising input and output for wires, and secondary user device of slave user equipment arranged against short circuit to control opening or closing of switching unit

摘要

The system (100) has slave user equipment (110) comprising an input and an output for wires (11, 12) of a power supply line (10) and a switching unit for coupling the input to the output. The input of the slave user equipment is connected with the output of master user equipment. The main user equipment monitors wires of the power source line against short circuit. A secondary user device (112) of the slave user equipment is arranged against short circuit to control opening or closing of the switching unit.