US 4,205,200 A · Digital communications system utilizing controllable field size

Abstract

A digital communication system employs a technique of effectively controlling the size of the bytes making up a field of data to be serially transmitted from one station to another, particularly one wherein the byte size may be selectively changed during the transmission of the data field. Assembly of a transmitted data field is controlled so that it includes an encoded data byte, termed a first pre-header byte, which contains information as to whether or not a change in the byte size of the data field is to occur. If the first pre-header byte indicates the occurrence of a byte size change, it also will contain a code representative of the size of the change. In addition, for a change in byte size, a second encoded data byte, termed a second pre-header or count byte is generated and immediately follows the first pre-header byte. The count byte contains information which specifies the length of that portion of the data field which precedes the occurrence of the change in byte size. Thereafter, following these pre-header bytes are a number of bytes of a first byte length (usually eight bits), which number is designated by the count byte, succeeded by those data bytes whose size is that specified in the first pre-header byte.

Claims14

Dependent claims

In a digital data communications system wherein data is assembled from its constituent bytes at a transmitter terminal, serially transmitted, and disassembled into its constituent bytes at a receiver terminal, a method of controlling the byte size of the data serially transmitted from said transmitter terminal and received at said receiver terminal without the use of filler bits, comprising the steps of:

at the transmitter terminal,
generating a first byte which contains information as to whether there is to occur a change in the size of data bytes transmitted, and the size of the data bytes transmitted subsequent to the change,
generating a second byte which contains information representative of the number of data bytes to be transmitted prior to the change in byte size, and
transmitting said first and second bytes followed by the bytes of the data field to be transmitted, and
at the receiver terminal,
receiving the first and second bytes transmitted from said transmitter,
decoding the information contained in said first and second bytes relative to the size of the bytes of the data field, and
receiving said data field and disassembling said data field into the bytes of which it is composed in accordance with said decoding step.

5 more elements

In a digital data communication network wherein data is assembled from its constituent bytes at a transmitter terminal, serially transmitted, and disassembled into its constituent bytes at a receiver terminal without the use of filler bits, a system for controlling the byte size of the data serially transmitted from said transmitter terminal and received at said receiver terminal, comprising:

at said transmitter terminal,
first means for storing a first byte which contains information as to whether there is to occur a change in the size of data bytes of a transmitted data field, and the size of the data bytes transmitted subsequent to the change,
second means for storing a second byte which contains information representative of the number of data bytes to be transmitted prior to the change in byte size,
third means, coupled to said first and second means, for transmitting said first and second bytes and the data field, and
fourth means, coupled to said first, second, and third means, for causing said third means to transmit said number of data bytes while modifying the contents of said second means, and upon the contents of said second means being modified to reach a prescribed value, causing said third means to transmit the remainder of said data field in bytes the size of each of which is specified in the first byte stored in said first means.

2 more elements

Dependencies are inferred from the claim text.

Digital communications system utilizing controllable field size

Life of this patent

Digital communications system utilizing controllable field size

Life of this patent

Abstract

Claims14