An electropneumatic brake system, for a commercial vehicle which is provided for pulling a trailer, includes at least one service brake circuit configured to activate service brake actuators, a parking brake circuit having parking brake actuators on at least one axle, a trailer brake circuit configured to provide a trailer brake pressure at a trailer brake pressure port, and a manually actuatable operating unit in a driver's cab. The manually actuatable operating unit has a first operating element and a second operating element. In the case of actuation of the first operating element when the vehicle is driving, the parking brake actuators are activated and a trailer brake pressure is output at the trailer brake pressure port. In the case of actuation of the second operating element when the vehicle is driving, only a trailer brake pressure is output.