The processing unit is installed inside the sabotage protected central housing, together with the power supply, two accumulators, MIO device and other, optional devices (e.g.alarm transmission unit). Any attempt to gain access to the components in the central(e.g. drilling a hole, remove the cover, remove the housing from the wall, etc.) will be recognized as a attempt to sabotage the system.The central device provides the interface(s) to the outside world. Three bus connectionsand an Ethernet port with RJ-45 plug are available. The Ethernet connection is used to interface to a normal PC with configuration and/or security information management software. All data on the Ethernet bus are coded with a 384 Bit Blowfish algorithm.The CPU board uses a low power INTEL SA1110 processor with 32MB flash memory,32MB DRAM and 512kB SRAM. To backup the internal real time clock and the SRAM memory, a Lithium battery is installed on the CPU board.All wires to the central are fixed mechanically to the provided cable lugs with cable tiers.