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:
Oct. 20, 1992
Filed:
Oct. 04, 1991
John H Garthwaite, Coupeville, WA (US);
Clay A Stocklin, Redmond, WA (US);
David M Rollins, Monroe, WA (US);
Leviton Manufacturing Co., Inc., Little Neck, NY (US);
Abstract
A handheld battery-powered telecommunications test instrument for monitoring the status of a pair of wires. A tone-generating circuit generates a tone signal in response to the user manually selecting operation in a tone-generating mode. The instrument monitors the pair of wires to determine whether an on-hook, off-hook or ringing signal is present on the wires, and if present, generates an interrupt control signal through a microprocessor. Logic circuitry connected to the microprocessor results in connecting and disconnecting the tone-generating circuit and the pair of wires to selectively apply the tone signal to the wires. In response to the control signal and the user selecting the tone-generating mode, the microprocessor connects the tone-generation circuit to the pair of wires if no control signal is generated, and disconnects the tone-generating circuit if the control signal is generated. The presence of the on-hook, off-hook and ringing signals on the pair of wires is determined by measuring the voltage between the pair of wires. A menu is generated by the microprocessor from which the user can select the frequency and amplitude for the tone signal.