Circuit arrangement for a corrosion protection current feed and for a line test for two-wire lines

A DSL system for transmitting data via at least one two-wire line, comprising:

• a DSL transceiver to be coupled to a two-wire line via a transformer;
• a DSL control device;
• and
• at least one circuit arrangement, being comprised of a controllable ramp generator for producing a ramp voltage;
• at least one first test impedance to be connected to a first line of a two-wire line;
• at least one second test impedance to be connected to a second line of said two-wire line;
• at least one first and second controllable switch for connecting said ramp voltage to said first and second test impedances;
• and a programmable control device for controlling said ramp generator and said first and second controllable switches in such a way so that said ramp voltage is coupled to said two-wire line in order to produce a corrosion protection current;
• said control device switching at least one of said first and second test impedances to the respective of said first and second lines for a line test;
• and
• said DSL control device controlling said control device of said circuit arrangement via a DSL control bus, injecting test signals into said two-wire line in order to test said two-wire line and evaluating DSL signals received from said DSL transceiver via said two-wire line.