摘要 |
A data communication network system for interconnecting a group of heterogeneous computers, batch terminals and conversational terminals employing serial transmission techniques in a ring or loop configuration. Each computer or terminal is connected to the communication network via communications processor and a interface unit termed a node. The communications processor is responsible for network protocol and activities as well as for interfacing devices to the network. The node provides the only connection to the ring or loop and derives the clock for the communications processor as well as the node itself from the transmitted data. All information in the communication network is transmitted in a modified Mauchly format and will appear as n-bit data or control characters. A control character, which always precedes a data character, will either be the address of a node or a null. To read information from the network, the node must detect a control character which represents its address. To insert information into the network the node must detect a control character which represents a null. Communications between loops or rings is always via nodes.
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