Patent ID: 7788429

Claim:
A system for facilitating transfer of data, comprising: a. a single unidirectional data communication ring; b. a plurality of controllable access units spaced apart and coupled to the data communication ring, each access unit including a ring input, a secondary input, a ring output, and a secondary output, each access unit configured to couple a selected one of the ring input and the secondary input to the ring output, at least one of the controllable access units being a first cross-coupling access unit coupled to the data communication ring, the cross-coupling access unit including a ring input, a secondary input, a tertiary input, a ring output, a secondary output, and a tertiary output, the cross-coupling access unit configured to couple a selected one of the ring input and the tertiary input to the ring output, the cross-coupling access unit also configured to couple a selected one of the ring input and the tertiary input to the secondary output, the cross-coupling access unit also configured to couple a selected one of the ring input and the secondary input to the tertiary output; c. a plurality of data communicating entities, each entity coupled to a different controllable access unit; d. a first cross coupler that couples the secondary input of a selected controllable access unit to the secondary output of the first cross-coupling access unit and that couples the secondary output of the selected controllable access unit to the secondary input of the first cross-coupling access unit; and e. a control circuit that is configured to drive all of the access units into a predetermined state to facilitate simultaneous communication between more than two of the data communicating entities.