Before vs | plus can work at all, the device has to do some preliminary work. Data must be prepared. Two of the most important elements required by vs | plus are the inputs (detectors) and the outputs (signal groups). For the inputs, all the information that the device receives must be prepared so that it can be used in the vs | plus logic. For the outputs, the current states of the signals must be accepted so that vs | plus can update its internal variables. In a new run of vs | plus, it can recognise whether the switching commands have been executed.