The BAC is based on a 486 or Pentium industrial grade PC running a Unix operating system. The BAC is installed in a physically secure location within the building. Each floor in the building has a twisted-pair communication loop connected to the BAC. Control equipment is connected to the communication cable using a multi-drop configuration. The loop can be up to 1000m in length and can currently support up to 32 control devices. The communication cable can be broken in a single location without loss of function on the loop.
The BAC is also connected to a computer network to allow remote control, monitoring and card registration. Communication is achieved with the Remote Building Access Controller (RBAC) using TCP/IP and DES encryption. A modem in the BAC can also be connected to a phone line to provide access to the BAC even if the computer network has failed. The BAC can be configured with a minimum of 8 hours battery back-up.
The RBAC is primarily a software product allowing a PC running MS Windows to fully interface with the BAC through the RMIT computer network. Multiple RBACs can be linked to single BAC allowing many departments in a building to share a BAC and common access points while still maintaining unilateral control over their own areas. At least one RBAC in each department will have a card reader attached to the PC so that user cards can be registered.
The Card Reader is a hardware product manufactured at RMIT. The unit is usually mounted on the entry-side of doors and can directly control door locking hardware such as electric strikes. When a card is swiped the unit transmits a request to the BAC using the encrypted card data. The BAC processes this request and sends commands back to the card reader unit to perform the appropriate functions. These requests are usually processed within a tenth of a second so that fast user response is guaranteed. In addition to controlling the door locking hardware, the Card Reader has extensive tamper monitoring functions.
The Field Service Unit is another type of control equipment which can be used in the system. It is far more flexible in controlling door hardware and as such can control boom gates, roller doors, emergency and fire doors, electric mortice locks, electromagnetic locks and photocopiers. The Field Service Unit can also monitor up to 8 other devices including door open switches and movement detectors. The Field Service Unit can be used to provide power for up to 12 Card Readers and can interface to flashing lights and sirens.
NEXT PAGE: The Future
Back to AXESS Home Page