Brake system and method for controlling a brake system

A brake system (2) for a vehicle (1), commercial comprising:

• an electromechanical brake module (11.1, 11.2) that provides a service-brake function (FB) and a parking-brake function (FF),
• a first energy storage unit (15) that supplies energy to the brake module (11.1, 11.2), and
• an electric operating supply circuit (100) that is connected to the first energy storage unit (15) and selectively connects the first energy storage unit (15) to the brake module (11.1, 11.2),
• a second energy storage unit (25, 25.1) and an electrical redundancy supply circuit (200, 200.1) that is connected to the second energy storage unit, and
• a control module (16.1, 16.2) that is connected to the operating supply circuit (100) and the redundancy supply circuit (200, 200.1), and that
• wherein the control module (16.1, 16.2) is configured to switch from a first switching state, in which the first energy storage unit (15) supplies energy to the brake module (11.1, 11.2) via the operating supply circuit (100), to a second switching state, in which the second energy storage unit (25, 25.1) supplies energy to the brake module (11.1, 11.2) via the redundancy supply circuit (200, 200.1),
• wherein the control module (16.1, 16.2) is also configured to monitor an operating state of the operating supply circuit (100) and of the first energy storage unit