Browse Prior Art Database

Data Transmission System

IP.com Disclosure Number: IPCOM000073571D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 32K

Publishing Venue

IBM

Related People

Croisier, A: AUTHOR

Abstract

This is a loop type transmission system coupling a plurality of remote transceiving stations to a master transceiving station. The system comprises generating means at the master station for impressing a tone upon the loop. Each station includes circuits for propagating the tone if service is not requested. Other circuits at each station are provided for transmitting data upon the loop at the reception of the tone. Lastly, each station includes a transmitter for repropagating the tone upon the loop at the termination of transmission.

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Data Transmission System

This is a loop type transmission system coupling a plurality of remote transceiving stations to a master transceiving station. The system comprises generating means at the master station for impressing a tone upon the loop. Each station includes circuits for propagating the tone if service is not requested. Other circuits at each station are provided for transmitting data upon the loop at the reception of the tone. Lastly, each station includes a transmitter for repropagating the tone upon the loop at the termination of transmission.

There is shown a multidrop data transmission system between master unit 1 and a plurality of terminals A--N. When the master unit desires to receive data from the terminals, it sends a tone through its tone generator 3 over transmission line 7. This tone is first received by the most remote terminal N on path 8. Prior to the transmission of the tone by the master unit the data filled terminals have their respective switches 10 placed in a position which can couple filter device 13 on path 8. Filter device 13 passes the data but blocks the tone. The tone is received first by counter 11 of terminal N. Since N is to transmit data, then further propagation of the tone is blocked. Once the data is transmitted, device 13 is shortcircuited. This enables the tone sent by the master unit to reach the second data filled terminal.

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