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:
Aug. 31, 1999
Filed:
Feb. 14, 1997
Paul Sigurd Swanson, Monument, CO (US);
William Robert Marbaker, Colorado Springs, CO (US);
Fluke Corporation, Everett, WA (US);
Abstract
A circuit for sensing network speed in a test instrument for local area networks (LANs) is provided. After coupling the test instrument to the LAN of unknown speed, a link pulse is found among the twisted-wire pairs so that the test instrument is configured for the transmit and receive pairs. The link pulse is then coupled to a comparator that compares the received voltage against a predetermined reference voltage level to develop a trigger signal. The trigger signal is received by a timer circuit which measures time values from the link pulse. The time values are collected by a microprocessor are then compared against a decision value to reach a decision whether the test instrument is coupled to a link running 10BASE-T protocol, 100BASE-T protocol, or a 10/100 dual-speed device. After the decision has been determined, the appropriate chipset is then powered up and coupled to the LAN, thereby minimizing battery drain and preventing errors from being introduced in the LAN by the test instrument.