Bi-directional communication system

摘要

There is disclosed a communication system using a bi-directional bus, which includes a plurality of devices (e.g., TV image receiver or video tape recorder, etc.) connected to each other. Each device includes a transmit signal formation unit having a frame structure including an address field for specifying addresses of devices between which communication is carried out, a control field for specifying whether communication is carried out in the state where device on the receiving side is locked or in the state where that device is unlocked, and a data field for specifying data to be transmitted. For transmitting data having a data quantity greater than data capacity of the data field, the data is divided into a plurality of frames, an indication to lock device on the receiving side is given to control field of a frame transmitted first, and an indication to unlock that device is given to control field of a frame transmitted last. The transmit signal thus indicated is transmitted through the bi-directional bus by a bus output unit. In addition, there are also disclosed a transmitting method, a receiving method and a communication method, which can be applied to such a bi-directional bus system.