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. 07, 1985
Filed:
May. 19, 1983
Henri Carsalade, Antibes, FR;
Francois-Xavier Delaporte, Cagnes-sur-Mer, FR;
Jean-Pierre Pantani, Nice, FR;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A circuit for receiving signals from a device connected through a line meeting the requirements of EIA RS232C Standard, comprising a differential amplifier (2) receiving an input signal the amplitude of which is divided by factor k through input network (1). The switching threshold of amplifier (2) is variable and has a first value to ensure switching on the positive slope edge of the input signal and a second value to ensure switching on the negative slope edge. This circuit comprises circuits for detecting the status of the connected device, including a level detector (3) and a decision circuit (4) which, according to the outputs of the receiver and level detector (5), generates a signal indicating the status of the connected device. Integrators (5, 6) are provided for preventing the status indicating signal from changing its level when the input signal goes through zero or receives short noise pulses.