O&O operating image of Rosengarten depot
Herr Kuhnt (HAVAG) inspecting the new control technology.

Halle’s Rosengarten Tram Depot

Last year, Hallesche Verkehrs-AG (HAVAG) subjected itsRosengarten tram depot in the south of Halle on the river Saale to a makeover. The focus was on replacing the control technology and operating software which had become obsolete. Working closely together with the customer, we completed the project successfully on time.


Rosengarten tram depot was commissioned in 1997 with a HANNING & KAHL depot controller and a depot management system (VABdepot) from Verkehrsautomatisierung Berlin GmbH (VAB) and was very modern at that time. The decentralised control controllers based on PLC Simatic S5 were linked via Profibus. Computer-based operation was carried out on PCs which, as Profibus participants, had special interface cards. Wonderware’s process visualisation tool InTouch was used for operation & observation of the signalling installation. It was already possible to set secured routes across different control segments. The operating software was part of HANNING & KAHL’s scope of supply.


After over 20 years in operation, the technology is now obsolete. Spare parts are difficult to procure licenses have expired, and the technology is not compatible with today’s operating systems. There is no alternative to technical upgrading, and HAVAG appointed HANNING & KAHL and VAB to do the work. As part of the order, networking was to be switched to Ethernet, and the PLC controllers replaced by HN-P microprocessor controllers. In view of the fast paced of technical development, it would not be an exaggeration to speak of a generational change.


Transmission protocols on the basis of Ethernet are now standard for process-data communication on the process control-level and have almost completely replaced Profibus. The network components are reasonably priced and available in industrial standard; proprietary hardware is no longer necessary for workstation processors as each computer now has an Ethernet adapter. It is now easier to integrate the system into corporate networks, and the possibilities for remote operation are more convenient.

PDI and O&O

The generic process data interface (PDI) developed by HANNING & KAHL and VAB contains data types, application protocols and transmission procedures which are tailored specifically to the application field of tram infrastructure. It has proven itself in over 100 projects worldwide and forms the basis for the process-visualisation and operation products developed by Verkehrsautomatisierung Berlin GmbH. VAB’s Operate & Observe (O&O) works on the basis of the PDI. It was first productively set in 2004 and has been constantly developed ever since.

Central server

An essential part of the system is a communication server which connects the process-control and management-control levels. Transport authority IT departments are increasingly seeking to centralise and virtualise the productive servers. HAVAG has managed to do so with the Rosengarten project and made administration and operational management of their system much easier. The central server farm is located at Freiimfelder Straße.

Emergency plan - local operating station

In order to enable local operation of the secured routes even in the event of total connection failure between Rosengarten and Freiimfelder Straße, a local operating station was configured which contains a local communication server. Switch-over between normal operation and local operation is effected via a simple network changeover switch. This ensures that only one communication server is active at any given time.

New type of software distribution

HAVAG’s management-control system administrators have implemented a trend-setting solution. The client software is now only installed on the central server and started via Microsoft RemoteApp from the operator workstation computers. Graphics, sound output and file access function as if the software were installed locally. This type of software distribution is also used for the BMS depot management system and makes administration and distribution much easier. This also prevents unauthorised access and manipulation on the installation.

Depot harmonisation and further improvements

A number of innovations and improvements were designed and implemented in the course of order fulfilment. These include update of the O&O software for the second depot at Freiimfelder Straße, introduction of O&O registration via “Single Sign-On“ and feedback about train crossings from the BMS, and display thereof in O&O.

Exceptionally good cooperation

We would particularly like to mention the exceptionally good cooperation we had with the customer and with HANNING & KAHL in all phases of the project. With their constructive cooperation, our customer made a major contribution to the design of the solution and, at the same time, gave impulses for product improvements at Verkehrsautomatisierung Berlin GmbH. A win-win situation and by no means a given.  

Looking ahead

Many depot controllers which were installed by HANNING & KAHL in the East German states after the fall of the Berlin Wall, have meanwhile reached the end of their operating life and have to be replaced. Halle’s Rosengarten depot is just one of a number of depots like Rostock, Magdeburg and Dresden, where the generational change has already taken place – more will follow.