The safety level of the ZSB 2000 is the safe data processing centre of the ZSB 2000 interlocking. It consists as a rule of three modules (two communication and one route module), each having a duplicated computer system. In addition a service keyboard and a duplicated program and system data memory are provided in the safety level. Only data is processed in the safety level and no currents are set. The release of energy is carried out locally at the actuating element.
The field level represents the safe actuator level of the ZSB 2000 interlocking system. It consists of safe microcomputer systems, each is duplicated, for the controlling and monitoring of a defined function, the systems being located as a rule on the field element itself and thus not in the interlocking system building. System concept of ZSB 2000 makes possible to install the system in small rooms, concrete houses or carbinets (ca. 5 qm). Furthermore there is no special climatisation necessary. Controlling and supervision of the individual components are realised by standard interfaces. The communication between the levels, the modules and to field elements is realised via CAN-BUS (system bus, modules bus, element bus).