Abstract: A transceiver provides bidirectional optically isolated communication between two devices. A first output signal from the first device is input to the transceiver. Using parallel optical data links, an optical signal is generated in response to the first signal and is detected by a pair of light sensitive devices. These light sensitive devices cause a second signal, representative of the first signal, to be generated. The second signal is then conducted to the input terminal of the second device. In an alternate mode of operation, the transceiver receives a third signal from the second device. Using series optical data links, optical signals are generated in response to the third signal and are detected by light sensitive devices. These light sensitive devices cause a fourth signal, representative of the third signal, to be generated. The fourth signal is then conducted to the input terminal of the first device.

Abstract: Bidirectional addressable repeaters of a power line carrier communication system each include an address recognition and a receive and transmit control logic circuit having programmable zone and address identifying states for connection in plural repeating levels defining branch paths linking a central control terminal with multiple remote terminals via a distribution line network. Each repeater retransmits an interrogation message, provides its own repeater address modification, and remains in a response-wait status. The alerted repeaters define the predetermined route of branch paths for being sequentially activated by a response message. Simplified repeater response address formats are used and each repeater modified its address data upon response message retransmission. The desired sequentially occurring repeating transmissions are assured upon retransmission of both the interrogation and response messages.