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:
Jul. 12, 1983
Filed:
Jun. 23, 1981
Robert Boudault, Limours, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
A test system is used to test a modem whose modulator is constituted by a multivibrator which during normal operation produces two frequencies f.sub.1, f.sub.2 in response to the data signal and which is connected to a transmission filter. In response to a test control signal, the multivibrator is modified to supply two test frequencies f'.sub.1 =nf.sub.1, f'.sub.2 =nf.sub.2, n being substantially equal to the ratio F.sub.o /f.sub.o, F.sub.o being the average value of the frequencies received by the modem during normal operation, f.sub.o being the average value of the frequencies f.sub.1, f.sub.2 ; at the same time the transmission filter is modified to transmit the two frequencies f'.sub.1, f'.sub.2 in response to the test control signal.