Access Control Terminology

Alarm input: A device that is monitored by the access control panel. An alarm signal will be generated if the device is activated.

Anti-Passback: A feature that will not allow any card to re-enter unless it has been used to exit. This requires that readers be used for both entry and exit.

Central or on line processing: A system where all systems information is stored in a central location and all go or no-go decisions are made by this unit.

Distributed processing: An access control system where some of the system information is stored at the individual readers or controllers. This allows the system to operate when the host is down or not communicating.

Door forced open: A signal indicating that the door was opened without a valid card or request to exit device. This requires a status switch and either a request to Exit button or Read-In / Read-Out door.

Door held open: A signal that indicates that the door was held open longer than it should have been. This is used to prevent someone from using a card to enter and then leave the door open for others. This requires a status switch on the door.

Easy egress: A means of exiting where the person wishing to leave simply turns the doorknob to exit.

RTE button: A Request to exit button. A device that must be pushed in order to release the door.

Fail safe: Is a locking device that is unlocked when no power is applied.

Fail secure: Is a locking device that is locked when no power is applied. These are not normally used for exit doors since they cannot be unlocked during a power outage.

Break Glass Unit: A device mounted near the exit door that can be used to release the door in the event of an emergency.

MOV: Metal oxide varistor, a device used to prevent the emf generated by the locks from damaging the control.

MODEM: A MODulator dEMulator. An electronic device that allows communication between electronic devices.

PIN: A Personal Identification Number assigned to a user. It is used either by itself or in conjunction with a card.

Remote Host: A system where the main computer that controls the system is remotely located. It allows a single computer to control multiple systems.

Stand alone: A system where the entire system is contained in the card reader.

Shunt time: When a door is released the status switch is automatically "shunted" for a period of time to allow the person to enter/exit. If the time is exceeded a door held open signal will occur.

Status switch: A magnetic contact mounted on the controlled door. It is used to detect door held or door forced.

Time zones: "Schedules" that allow cards to function or not function depending on the time of day. This is used to limit access to the facility. The schedule may include not only time but which days of the week a card is valid.