A method includes accessing an electronic program guide. The switch comprises a controller and shelves providing communication capabilities for the switch. A shaft with a cleaning device for the spray nozzles or for the inner wall of the pipeline is disposed within the pipeline. A method for operating the drive apparatus includes the steps of changing from one operational mode to another mode and subsequently moving the drive apparatus to a desired position. The display system receives a signal notifying about activation of the lighting device from the lighting controller that provides onoff control of the device; the system then determines the effective image area if the device is on, and does not if it is off. The test images are periodically moving test images, and the visual function is determined on the basis of detecting the phenomenon of optokinetic nystagmus.