An interface (12) for a lamp operating device (13) has two input-side terminals (1, 2) for the connection of bus lines or for connection with a button or switch, an evaluation logic (3) for the processing of signals present at the input-side terminals (1, 2) and for the generation of output-side signals for the control of the lamp operating device (3), and at least one electrical isolation element (4) to electrically decouple the input-side terminals (1, 2) from the lamp operating device (13). Thereby, the evaluation logic (3) is arranged on that side of the electrical isolation element (4) which is towards the input-side terminals (1, 2), and is supplied with voltage via the input-side terminals (1, 2) of the interface (12).