Anti-Pass Back (APB) is to prevent the cardholder from handing his card to another person to use. To use anti-pass back, you would typically have a reader on both the entrance and the exit sides of the door. Once the cardholder has used his card on the entrance, the card cannot be used again at the entrance until it has been shown to have used the exit.
Anti-pass back (APB) is most commonly used in car parks and on turnstiles on construction sites or sites using the access control system as a form of time and attendance.

APB is a proven and effective way of managing car park spaces as it prevents a second car access on the same credential. For T&A situations it can also prevent people from presenting their friend/colleague’s cards as it will not work again to allow the late colleague through unless the badge was clocked out again.

There are a few types of anti-pass back known as hard, soft and timed. In a timed setup, the cardholder is only blocked out for a set period of time on an APB violation. Soft anti-pass back still allows the cardholder access yet notifies the access control systems operator that this has occurred. In hard anti-pass, the APB rules are strictly followed: cardholders are denied access to a violation of the APB rule.

When using anti-pass back, it is always best practice to wire a door contact. The access control system can be set to only move a cardholder from one area to another unless it sees a valid card followed by a movement in the door rather than just the valid card being presented.

Both VantagePoint and GuardPoint Pro can use all types of anti-pass back. VantagePoint is unique in that the controllers can update APB movements to each of its controllers over an ethernet and without the server software running.

To learn how to setup anti-pass back in VantagePoint see:

https://sensoraccess-vp.zendesk.com/hc/en-us/articles/205768541-Configuring-Anti-Pass-Back