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:
May. 09, 2000
Filed:
May. 09, 1997
Jeffrey Ying, Glendora, CA (US);
I/O Control Corporation, Azusa, CA (US);
Abstract
A multi-tier, master-slave control network having redundant backup for a master node in which the slave nodes are provided with means for detecting a failure of the master node and for taking over for the master node in such circumstances. The master node and slave nodes are connected to a common bus. Each of the slave nodes has an uplink transceiver and a downlink transceiver, with the downlink transceiver ordinarily isolated by switches from the common bus. Each of the slave nodes has a timer programmed with a separate failure mode detection time period. When a slave mode fails to receive control messages from the master node for a period exceeding its programmed failure mode detection time period, the slave node takes over for the master node. Because each slave node has a separate failure mode detection time period, a priority is established in which the slave nodes will take over for the master node, and redundant master backup control is provided. A preferred embodiment of the control network has multiple buses, one bus for each tier, and each bus has a master node and a plurality of slave nodes, with each of the slave nodes capable of taking over for the master node on the slave node's particular bus.