Electronically controllable braking system having two levels of redundancy

An electronically controllable braking system, in particular an electronically controllable pneumatic braking system, for a vehicle, in particular a commercial vehicle, the electronically controllable braking system comprising:

• a service brake system including:
• a front axle brake circuit with a front axle modulator and front axle brakes connected thereto,
• a rear axle brake circuit with rear axle brakes, and
• a central control module connected to a vehicle BUS,
• wherein a front axle service brake pressure can be supplied to the front axle brakes and a rear axle service brake pressure can be supplied to the rear axle brakes, and the central control module is configured to generate a service brake control signal in dependence upon a braking specification, wherein the front axle service brake pressure and rear axle service brake pressure can be generated in dependence upon the service brake control signal and specified to the front axle brakes and rear axle brakes, respectively, under the electrical control of the central control module for implementation of the braking specification via the front axle brake circuit and the rear axle brake circuit;
• and
• a parking brake circuit including a parking brake module configured, in the event of a defect in the central control module, to process the braking specification and to output, at least in dependence upon the braking specification, a rear axle redundancy brake pressure to spring-brake parts for redundant implementation of the braking specification;
• wherein
• the front axle modulator is connected to the central control module for receiving the service brake control signal and outputting the front axle service brake pressure to the front axle brakes in dependence upon the service brake control signal,
• the front axle modulator is further configured, in the event of a further defect in the parking brake module, to process the braking specification and to output, at least in dependence upon the braking specification, a front axle redundancy brake pressure to the front axle brakes for the redundant implementation of the braking specification.