Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
191 words
A method of measuring, under running conditions, operation parameters of an interface circuit (2) and of a telephone subscriber line (3) connected to it, with said interface circuit comprising a first integrated circuit (6) operating on a high voltage with first outputs (R,T) connected to said line (3) and second outputs (IT,IL) on which transverse and longitudinal electric current values of the line (3) appear respectively during normal operation, and a second integrated circuit (7) operating on a low voltage between the first circuit (6) and a telephone exchange (8), comprising the steps of: - switching said outputs (R,T) to the opposed ends of an impedance (Zn) having a predetermined value; - measuring, by means of said first circuit (6), the values of the currents present on said second outputs (IT,IL); - again switching said outputs (R,T) between leads (A,B) in said line; - measuring, by means of said first circuit (6), the values of transverse (It) and longitudinal (Il) currents of said line (3); - for each measurement, encoding the measured values in digital form, using said second circuit (7), and transmitting the values thus encoded to the telephone exchange.
Claim 2
Dependent Claim
33 words
A method according to Claim 1, characterized in that the second measurement step comprises sub-steps which are carried out by alternately driving one of said outputs (R,T) to a state of high impedance.
Claim 3
Dependent Claim
37 words
A method according to Claim 2, characterized in that said state of high impedance is achieved by turning off a corresponding amplifier final stage (14,15) incorporated to said first portion (6) at each of said outputs (R,T).
Claim 4
Dependent Claim
24 words
A method according to Claim 3, chatacterized in that said amplifier final stage is turned off by cutting out the polarization current supplied thereto.
Claim 5
Dependent Claim
26 words
A method according to Claim 2, characterized in that a measurement with an output (R) at a high impedance is taken in the reversed battery mode.
Claim 6
Dependent Claim
17 words
A method according to Claim 1, characterized in that said digital code is of the PCM type.
Claim 7
Dependent Claim
190 words
A circuit device (1) for measuring, under running conditions, operation parameters of an interface circuit (2) and a telephone subscriber line (3) connected to it, said interface circuit comprising a first integrated circuit (6) operating on a high voltage with first outputs (R,T) connected to the line (3) and second outputs (IT,IL) on which transverse and longitudinal current values of the line (3) appear respectively during normal operation, and a second integrated circuit (7) operating on a low voltage between the first circuit (6) and a telephone exchange (8), characterized in that - with each of said outputs (R,T) there corresponds an amplifier final stage (14,15) having an enable input (NA,NB) on which a polarization current is supplied, and - a pair of power supply inputs (NP,RP) respectively receiving a negative voltage value and another, even more negative value relative to ground, - electronic means being arranged to link operatively said inputs to command and enable signals applied to inputs (11,12) of said first circuit (6), whereby said outputs (R,T) can be switched in a mutually excluding manner to respective states of high impedance and optionally with their polarities reversed.
Claim 8
Dependent Claim
23 words
A device according to Claim 7, characterized in that said means are effective to cut out the polarization current of said amplifiers (14,15).
Claim 9
Dependent Claim
30 words
A device according to Claim 7, characterized in that said amplifier stages (14,15) include additional selection inputs (CP,RP) adapted to enable power supply of said amplifier with a selected polarity.