Visual act recently completed the installation of a new control system for the Norwegian Theatre in Oslo. The company replaced the drive electronics for 119 fly bars and point hoists; the new system installed is capable of operating all the drives simultaneously.

Three operator desks were installed. The latest version of Visual act's operator desk was selected since it is especially designed for permanent installations. It provides an ergonomic work area suitable for many hours of use on an everyday basis. One operator desk is wireless and can be moved to the house for rehearsals.

The control system has fully redundant servers and positioning computers. Failure of a component will not stop the system. It is possible to make tests and backups as well as replace components without pausing work on the stage.

Intelligent drives communicating over Profibus replaced the existing centralized system. This resulted in the removal of 8 tonnes of cable. A second Profibus system handles the absolute encoders, allowing for independent control of position and safety.

The existing machinery incorporated both DC and AC motors. This is now transparent to the user: each drive is handled in the same way, with the same properties and messages.

Visual act believes that this type of installation will be more common, as it is possible to update a system to the latest standards without a total refit of winches and mechanics. Customers' demands for greater efficiency and to meet the latest safety standards can be handled within a reasonable budget. The system is both economical and at the forefront of technology.

The work was done in close cooperation with Visual act partners Browik El and Lönne Maskin.