A selector switch for a supervisory remote control system is provided. This control system comprises operation terminals such as switches and control terminals such as relays, and a signal line for connecting a signal transmission unit to the operation and control terminals. Each of the operation and control terminals has an individual address. The transmission unit provides a control signal to the signal line according to a time-division-multiplexing manner such that when one of the operation terminals is operated, a load connected to the control terminal in an address correspondence with the operation terminal can be controlled. The selector switch comprises a data receiver for receiving data including conditions of loads connected to the control terminals from the transmission unit through the signal line, a memory for storing the data received by the data receiver, a selector for selecting desired information from the data in the memory, and an output unit for providing the desired information to an external device such as personal computers according to an order of the selector.