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:
Sep. 13, 2005
Filed:
Sep. 08, 2000
Dan Dean Christensen, Austin, TX (US);
Ram Ramachandran, Austin, TX (US);
Dan Dean Christensen, Austin, TX (US);
Ram Ramachandran, Austin, TX (US);
Fisher-Rosemount Systems, Inc., Austin, TX (US);
Abstract
A hand-held communication control device which, when coupled to a process control system communication bus, controls communication occurring on the bus using a communication schedule that dictates when each of the devices coupled to the bus will be permitted to communicate on the bus. The hand-held communication control device further uses a probing algorithm to detect devices, including other communication control devices, that are coupled to the bus. The probing algorithm causes the hand-held communication control device to select an address from one of a set of three address lists to which a probe node message is then transmitted to detect the presence of a device at that address. One of the address lists is reserved for communication control devices and uses only a limited number of maximum possible addresses. The probe addresses are selected from each of the three address lists in a sequential manner and from among the three address lists in an alternating manner so that, when the communication control device takes control of a bus formerly controlled by another communication control device, the hand-held communication control device detects the presence of the other communication control device and relinquishes control of the bus to the other communication control device in a timely manner.