Patent ID: 7519130

Claim:
A method of receiving data, comprising: utilizing a control signal at a data receiver to switch between an alternating current (AC) transmission receiving mode for receiving an AC coupled mode data signal from a pair of differential signal inputs and a direct current (DC) transmission receiving mode for receiving a DC coupled mode data signal from the pair of differential signal inputs; and operating the data receiver while compensating for DC voltage offset during the AC transmission receiving mode when the offset compensation circuit is enabled, operating the data receiver without compensating for DC voltage offset during the AC transmission receiving mode when the offset compensation circuit is disabled, operating the data receiver while compensating for DC voltage offset during the DC transmission receiving mode when the offset compensation circuit is enabled, and operating the data receiver during the DC transmission receiving mode without compensating for DC voltage offset; injecting in an upchannel direction, onto transmission lines provided for carrying the differential signal inputs a first test data signal onto a first one of the transmission lines operable to carry a first one of the differential signal inputs, and a second test data signal onto a second one of the transmission lines operable to carry a second one of the differential signal inputs; and at a transmitter connected to at least one of the first and second transmission lines, detecting faults on the at least one of the first and second transmission lines.