Connection of a two-wire line to the exchange with CYFRAL door intercoms of types TD3, TD4, TD6. The function keys CC-1000/1500 are located at the base near the receiver. Key 1 is the function key for opening the front door. Key 2 is multifunctional and allows, for example, the lighting to be turned on or the electric door opener to be activated without lifting the receiver. There is the option to adjust the call volume and deactivate the conversation privacy, allowing tenant conversations to take place. Additionally, the phone can easily be converted into a version with a wired listening function without the need to solder the power supply from the intercoms.