Honeywell Regelsysteme commissioned InterFace Computer of Germany to develop programs to interface various tools used in a complex building control system:

In the state-of-the-art buildings it is essential to monitor, manage and control temperature, air-conditioning, water and electricity supply in a integrated manner.

In the new Munich airport terminal 2 building all the above mentioned environment factors as well as ramps and luggage conveyor belts are controlled by a single system.

Honewell has developed a monitoring system (DXO-GOI) based on DataViews, a real time graphical user interface, which displays the present status of the various environment factors.

The installed subsystems come from various manufacturers, among others Philips. The subsystems provide the process visualization on their own. In order to show these pictures under DXO-GOI system some 600 pictures had to be translated to DataViews. The Philips-pictures were available in un- documented ASCII-Format. Translation meant to supply the same information (instruments, color-changes, information presented along a polygon) as well as attaching "datapoints" of the other system.

The solution was implemented as a three-step transformation: (1) reading of the source without modifying the information, (2) preprocessing, including marking objects in the topo- logical neighborhood, and searching for transformation-relevant patterns and (3) generating DataViews objects using the pre- processing information.

The scanning of the process images was done with Lex. Selected functions of the DV-tools library (DataViews library) were connected on the target-side. All relationships between source- and targetside were expressed as Prolog facts.

Prolog is advantageous as compared to other programming languages as the data-structures do not have to be declared somewhere else. Also advantegeous for the enhancement of the symbolic information because there is no overhead for the memory-management of dynamic structures. The conversion from source to target is described solely by fact-tables and rules.

UNIX Workstation
IF/Prolog, DataViews, Lex