C•CURE 800/8000 Software Configuration Guide - Tyco Security ...

AntipassbackHow Cluster Antipassback Decision is MadeIn iSTAR clusters, antipassback information is stored locally on the clustermaster. When an iSTAR member controller is online and a card is presented atits reader:• The member sends a request to the master for antipassback information.• The master replies with the appropriate antipassback information (admitor deny).• If reply was an admit, then member reports whether the door was used.As long as the communication within the cluster is good, the cluster membersdo not store any antipassback information.How Cluster Antipassback Works During CommunicationsFailureWhen the cluster members lose communication with the cluster master, themembers begin to enforce antipassback locally depending upon the FailureMode you configure for the cluster. The member starts out with noantipassback data, all cards are initially graced. As the cards move throughthe cluster the member collects antipassback data locally. If the failure modeis:• No Access, the card is always denied access if there is no record of thecards last location.• Local, the card is admitted if the member does not have sufficientinformation about the card to make an antipassback decision.Restoring CommunicationOnce the communication of a member is restored to the master, a memberwaits exactly 16 sec*[size of cluster + 1] before uploading cardholder locationsto the master. The master then compares the time recorded in the memberwith the time recorded on the master and retains the latest recorded locationfor a cardholder. Once this upload is complete, the member deletes theantipassback data stored locally and returns to requesting this informationfrom the master normally.2–36 C•CURE 800/8000 Software Configuration Guide