====== FUNCTION ======

When the person enters the building and stands before the safe gate, presence sensor is triggered. LED and graphical display show required conditions to enter.

Firstly, the disinfection should be applied and face scan performed, if necessary. Face scanner checks if the person is wearing a mask and if his body temperature is normal. Then one of two steps is required to enter. Person must scan its card, to determine its level of access and if it had completed all of the necessary steps for that level. Alternate option is that receptionist opens the door. After completing the necessary steps, button for allowing L1 and/or L2 access become enabled, receptionist then confirms person's level of access and it can enter. 

Next to the door is a semaphore. If the red light is on, that means you didn't complete all of the required conditions to enter. If, along with red light, alarm starts beeping too, the person must leave the building immediately. This happens for example if fever is detected. When the green light on the semaphore turns on, the person is clear to enter. 

It's possible that the limit of people is reached. If that happens, person can't enter the building even if all of the required conditions were completed. First limit is for L1, person with that access can't enter after that limit is reached. Second limit is for L2. After that limit is reached, only UL access is allowed inside (employees). 

There are two allowance types, permission and prevention. If permission is selected, doors are closed until all condition are fulfilled, after which they open. If the prevention is selected, doors are open. If person fails to meet all conditions, doors close.