The term display element is a generic term for all possible types of displays that can be controlled with an on/off command in control devices. Typically, a display element corresponds to a signal group.
Figure 4: From traffic stream to signal groups
The traffic stream controls the display elements. A traffic stream can influence several display elements simultaneously. The commands for the display elements are transferred to the control unit via the interface. Depending on the type of display element, the digital outputs (relay, indicator) or the signal groups are addressed. The control unit checks the signals and then transmits them to the corresponding signalling devices.