If you are using Q96x, VMGB-6xx or other People Counting devices, you can use them for the Tailgating detection function on your access control device.
The basic algorithm or logic of Tailgating is defined as the number of registered users of a particular swiped card should match the number of persons passing by.
If this condition is not met, then a Tailgating event is triggered. So, when an I/O device, such as a warning light, is connected to the access control device and a tailgating event occur, the alarm light will be triggered.