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:
Apr. 01, 1997
Filed:
Mar. 20, 1995
Robert B Walance, Newbury Park, CA (US);
Harris Corporation, Melbourne, FL (US);
Abstract
The possibility of corrupting digital data traffic carried by a data line (powered or unpowered), by the connection of a telephone test set to the data line is effectively prevented by augmenting the telephone test set with a mechanism that prevents the test set from asserting an OFF-HOOK condition on the line, unless it has been determined that each of two conditions are satisfied. These conditions are: 1- that no digital data traffic is being carried by the line; and 2- that the electrical voltage condition of the line satisfies a prescribed minimum voltage level criterion. If either of these conditions is not satisfied, a switch circuit installed in the test set's connection path to the line is maintained in a default, open condition, so that it is effectively impossible for the line to be presented with an OFF-HOOK condition through operation of the test set. This default condition remains in effect until both criterion are fulfilled. As a further safety precaution, should the line to which the test set is connected be determined to be carrying digital data traffic, the invention causes an audible alert tone to be generated as a warning signal to the craftsperson.