The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 29, 1994
Filed:
Nov. 15, 1990
A Gregory Rocco, Jr, Carlisle, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A subring module for controlling the switching of a subring in and out of the main network of a token passing ring has a data detection circuit for detecting a token on the network. The subring module switches between two switch positions in response to an internal state machine. The first switch position incorporates the subring into the main network, and the second switch position isolates the subring from main network. The subring module has a state machine which responds to the detection of the token on the network to switch the subring out of the network when the network is down, and to switch the subring back into the network when both the subring and the main network are up again. When a number of subrings are present, each subring has its own module and state machine control. When the network goes down, the subrings switch out at different times depending on a hierarchial priority given to the subrings. The switching of the subrings back into the network is also controlled relative to a hierarchical priority. Thus, splitting and recombining of subrings of the the token passing ring can be arranged to proceed in any desired manner. The end result is that a defective subring is automatically isolated.