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:
Dec. 30, 1986
Filed:
Sep. 14, 1984
Ralph O Skatrud, Raleigh, NC (US);
Chester L Storm, Hillsville, VA (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
Terminals in a serial loop communication system monitor the loop to detect a unique polling message. Failure to detect the polling message forces the terminals into an error checking routine. The routine quiesces (i.e., forces most of the stations into a quiet state) the loop with only one active station issuing a beacon message. The active station monitors the loop and when the beacon message is detected, the station issues an error message signifying that the controller is down. The error message is used to activate a backup controller. The error routine further identifies a break or other defect in the loop if its own beacon message or any other beacon message (or a poll) is not received.