In contrast to the familiar signalling times, the frame signal is used in vs | plus. A frame signal is no longer interpreted as a switching command for a signal group, as is the case with signal times, but is used as a control signal for the traffic-dependent control of a traffic stream, as briefly mentioned above. The frame signal is defined for each traffic stream. This means that each traffic unit can be directly influenced, i.e. controlled.
The frame signal itself is divided into a logon area and an extension area. Requests are handled in the signalling area and lead to switch-on commands. As soon as the traffic stream is green, it can be extended in the signalling area, i.e. the extension area becomes active.
In the call area, the traffic stream can change from red to green. In the extension area, the traffic stream must already be green so that the traffic stream can extend to the end of the area.
The advance zone enables the green light of a traffic stream to be switched earlier. This advance zone is activated by an PT request.
Figure 9: Frame signal pointer
The frame signal pointer defines a point in time in the cycle at which the next traffic stream to be processed (according to the main series) is to be considered for the control (Control management).
The sum of the frame signals of all traffic streams results in the so-called frame signal plan.