Data transmission systems

Claim 1

A data handling and transmission system comprising: a. a common data communication highway arranged in a closed loop and having an information path for the passage of address and data information and a control path for the passage of control signals indicative of the type of information on said information path; and b. a plurality of data handling stations interconnected by said common data communication highway for communication between any one and any other thereof, each said station having i. first means connected to said common data communication highway for transmitting information and control signals thereon; ii. second means connected to said common data communication highway for receiving information and control signals therefrom, iii. an interconnecting path connecting said first means and said second means, iv. third means for breaking said interconnecting path, v. fourth means for storing an own station priority number, vi. fifth means connecTed to said second means and said fourth means for comparing said own station priority number stored in said fourth means with information received from said common data communication highway by said second means, vii. sixth means connected to said common data communication highway for determining whether said highway is free, and viii. seventh means responsive to the station requiring to communicate with one of the other stations over said common data communication highway to connect said fourth means to said first means so as to apply said own station priority number to said first means; to operate said third means to break said interconnecting path; to activate said sixth means and responsive to an indication therefrom that said highway is free to activate said first, second and fifth means so that said own station priority number is applied to said information path, a priority number indicating code is applied to said control path and said information received is compared with said own station priority number to determine its relationship thereto; and responsive to an indication by said fifth means that said information received is greater than said own station priority number to release said third means to restore said interconnecting path and to disconnect said first and fourth means so that said own station priority number is removed from said first means. CM,2A handling and transmission system as defined in claim 1 wherein said seventh means in each station includes sequence control means responsive to said information received being equal to said own station priority number to remove said own station priority number from said first means and to replace it by a destination address indicative of the destination data handling station with which communication is required; and wherein said first means in each station is operative to transmit said destination address on said information path and to transmit a destination character code on said control path.