BUES 2000 is the first control system for level crossing installations to consist entirely of electronic components. A multicomputer system incorporating a 2v2 safety structure with information duplication throughout and an intelligent bus system (CAN) creates a safety structure which enables the control of all processes, such as the reliable acquisition, processing, evaluation and output of information and, for the first time, a detailed diagnosis interface for maintenance and servicing purposes. The system’s modular design enables swift adaption to the specific monitoring and application variants for the individual level crossing concerned.

Monitoring variants

• Fü Remote monitoring
• Hp Station signal monitoring
• ÜS Monitoring with signal BÜ 0/1 or So16a/b
• Vk Availability control
• Bed Operator monitoring

Combinations of these basic monitoring principles are, of course, applied (e.g. Hp-Fü; Hp-ÜS).

Application variants

• LZ Light signal amber/red
• Bli Flashing light
• H Half-way barrier
• HH Complete stop with 2 half-way barriers
• V F ull barrier
• F Side path barrier
• V(A) Pointsman-operated on-call barrier
• V(AS) On-call barrier with self-service facility

Expansion variants

All actuating elements at the level crossing are controlled and monitored fully electronically. Due to its compatibility with old and new plant components alike, the BUES 2000 is suitable not only for new installations, but also for integration into existing level crossing plants. The following expansion variants are possible in the basic system:

• 32 light signals (amber/red, with main wire and auxiliary wire)
• 64 flashing lights (red, with main wire and auxiliary wire)
• 32 barrier drives
• 2 tracks
• Implementation of special circuits, such as WS, SF-12, etc.
• User-definable time control of barriers (H, HH, V) and light signals (LZ, vLZ, Bli) Control of light programmes, such as BüSTRA

Technical design

The nucleus of the BUES 2000 system is divided into 3 logical levels:

• Management level
• Control level
• Field level

Similarly to the EBÜT80 level crossing technology, tasks are distributed to various modules within the levels which involve signalling tasks of relevance to safety (control and field levels). A distinction is made between 

central module: Coordination and control of the level crossing process

light / barrier module: Control and monitoring of light points (LZ, vLZ, Bli), light programmes (BÜSTRA) and barriers

track module: Recording and relaying of all information received from the track and all appurtenant data,  

whereby the number of modules can be altered according to the expansion level of the installation. Each module essentially represents a 2v2 computer unit whose actuating components are connected to the installation via an intelligent field level.

Management level

This level performs tasks which are not of direct relevance to safe signalling operations, such as diagnosis. A diagnosis module, consisting of an IBM-compatible PC, is integrated into the system for this purpose. This module collects information from the system in non-interactive mode, decodes the data and carries out an initial assessment. On the basis of these detailed data, it has been possible for the first time to develop a specific maintenance and servicing concept for level crossing installations.

Control level

This level performs control and monitoring functions which are of relevance to safe signalling operations in the respective modules by means of module processors. The doubled components of the field level are examined and diagnostic data is provided for the management level.

The integrated central programme and plant memory, ZPAS, which is incorporated as a module in the control level, contains the standard programmes together with the specific data for the level crossing concerned. When the system is started up, the individual modules are loaded accordingly.

The service keypad enables the calling of information from the BUES 2000 and the prompting of various plant responses via a 4-line display and a keypad.

Field level

This level implements the interface to the actuating elements which is required to ensure safe signalling operations. Each card of the field level can be used up to 16 times in the module concerned.

IN/OUT module:

It offers 16 inputs and 4 outputs and can be employed wherever interfaces of this type (signal box, manual push-buttons) require to be operated, independently of any specific modules.

Signal module:

It enables 4 light points to be controlled (main and auxiliary wire). This module is employed primarily to control monitoring signals for level crossings.

SST module (barrier control module):

It enables 2 barrier drives to be controlled.

LST module (light control module):

It enables 4 light points (main and auxiliary wire) to be controlled, whereby a distinction is made between the actuation of amber and red lights (LSTG, LSTR).

CAN 10/200 module:

It enables message-oriented communications between the BUES 2000 and intelligent field elements (e.g. barrier drive HSM 10E). For this purpose the CAN bus, which performs the communications functions within the BUES 2000, is connected directly to the control computer of the actuating field element, without requiring any special control logic within the BUES 2000. To enable communications over large distances, the transmission rate is reduced from 200 to 10 kBaud.

Data transmission via CAN

Communications between the respective levels and within the modules are effected via the CAN bus. CAN stands for Controller Area Network, and is a serial, inherently intelligent data transmission system. This system incorporates a number of error detection measures, including

• bit error monitoring
• 15-bit CRC block monitoring
• format monitoring ...

To further enhance safety, polling has been introduced in the 2v2 system. Polling is a method which is employed in multiple access systems of this type to scan the individual stations periodically and, at the same time, to transport information.