Conventions for Digital Data Communication Link Design

A definitive set of conventions has been established for the automatic, synchronous transmission of digital data over half-duplex (nonsimultaneous) communication links. Provision has been made for communication between diferent device types and between computer processing units. Although one transmission code must be used on a given data communication link, a special feature permits digital data in any form to be transmitted, including encrypted data and compiled computer programs. This paper describes the Binary Synchronus Communication (BSC) conventions, which prescribe the encoding of data, the procedures for synchronizing stations, the methods for controlling the data links, transmission message formats, and error detection and correction methods. The presentation is sufficiently detailed to indicate the kinds of design decisions that are involved in setting up automatic data communication links.