The unit counts the number of users present in a specific area, if the predefined maximum number is reached access will be denied until a user leaves a place free by leaving the area. This may be the case in the management logic of a parking lot or of an area where for security reasons no more than a certain amount of users may be present.
The system is called impartial because it fully autonomously decides to deny access o a person requesting it in order to proceed with a check. The parameter on which the impartial system is based is a random generator which simulates the extraction from a container of a black ball out of every “X” red ones.
The interlocking unit controls the opening of two or more doors verifying that when a request is made for a new opening all doors are correctly closed and allowing only one door at a time to open. This increases security and prevents two doors left open to allow continuous and uncontrolled passages.