A system comprising: a plurality of access controllers , wherein each of the plurality of access controllers is located at a respective one of a plurality of sites and is in communication with a corresponding anti-pass back compatible card reader ; a host system that supports each of the plurality of access controllers; wherein a first of the plurality of access controllers is configured to receive a triggering event in response to a valid card transaction occurring at the corresponding anti-pass back compatible card reader, and in response to receiving a triggering event, the first of the plurality of access controllers is configured to transmit a triggering signal to the host system, wherein the host system is configured to receive the triggering signal, and in response to receiving the triggering signal, the host system is configured to: identify a first site of the plurality of sites at which the first of the plurality of access controllers is located; determine a sub-set of the plurality of access controllers that are associated with the first site of the plurality of sites at which the first of the plurality of access controllers is located; transmit a status update to the sub-set of the plurality of access controllers, wherein the status update includes an anti-pass back status update; and not transmit the status update to each of the plurality of access controllers outside of the sub-set of the plurality of access controllers. a plurality of access controllers , wherein each of the plurality of access controllers is located at a respective one of a plurality of sites and is in communication with a corresponding anti-pass back compatible card reader ; a host system that supports each of the plurality of access controllers; wherein a first of the plurality of access controllers is configured to receive a triggering event in response to a valid card transaction occurring at the corresponding anti-pass back compatible card reader, and in response to receiving a triggering event, the first of the plurality of access controllers is configured to transmit a triggering signal to the host system, wherein the host system is configured to receive the triggering signal, and in response to receiving the triggering signal, the host system is configured to: identify a first site of the plurality of sites at which the first of the plurality of access controllers is located; determine a sub-set of the plurality of access controllers that are associated with the first site of the plurality of sites at which the first of the plurality of access controllers is located; transmit a status update to the sub-set of the plurality of access controllers, wherein the status update includes an anti-pass back status update; and not transmit the status update to each of the plurality of access controllers outside of the sub-set of the plurality of access controllers. identify a first site of the plurality of sites at which the first of the plurality of access controllers is located; determine a sub-set of the plurality of access controllers that are associated with the first site of the plurality of sites at which the first of the plurality of access controllers is located; transmit a status update to the sub-set of the plurality of access controllers, wherein the status update includes an anti-pass back status update; and not transmit the status update to each of the plurality of access controllers outside of the sub-set of the plurality of access controllers. <EOS>