The experiment was designed to demonstrate the data transmission capab
ilities of a langunge-oriented data system (GDL). In a realistic simul
ation, an unknown computer-controlled substation was connected to a co
ntrol centre. By inquiry to the substation, the control centre compute
r got informed on the stock of objects and the topological connections
in this substation, then designed inter active diagrams for its switc
hyards. Finally, this substation was controlled as for switching and t
ransformer tapping by nit operator. The time required to couple the pr
eviously unknown substation to the control system amounted to 100 s.