This month sees the start of a new Masterclass series on specifying and installing access control systems, written by Richard Herkes of PAC International
Over the next few months this series will set out to explain the principles of integrated access control in a plain and easily understood way. It will take in system design, choice of equipment, cabling and networking. Collected together with a glossary of terms, it will make a useful reference guide for installers.

What are the benefits?
I would like to start by explaining the benefits of integrated access control.

Access control is a means of controlling and monitoring the movement of people and vehicles through secured access points such as doors, turnstiles and car park barriers. Systems allow you to decide who goes where and when, so that only authorised personnel may gain entry to secure buildings or areas, and at the times allocated by the system administrator.

Modern access control systems are reliable, flexible and easy to use. Today's highly sophisticated electronic systems can manage anything from one door to a network of hundreds of doors on several sites.

Traditional mechanical keys pose a security risk if a key is lost or stolen because the locks must be changed and new keys cut. An electronic ID (identification) device, however, can simply be deleted from the system if it goes missing and a new ID issued to the individual, without disruption to other users.

Other major benefits of access control systems are:

  • The ability to monitor where people are in the building
  • A management record of where people have been
  • Access restricted to certain areas (for both employees and visitors)
  • Access restricted to certain times
  • Only one ID device is required for multiple sites
  • Alarm monitoring and management (e.g. intruder, door forced, fire)
  • Management of multiple remote sites
  • Integration with other building management systems.

Access control equipment can be linked to other facilities such as fire doors, elevators, lighting, paging, lone worker protection, time and attendance, CCTV, perimeter fencing and cashless vending systems, to name but a few.

A future article will have more information on system integration and the concept of alarm monitoring and management. (If you have specific systems you want to link to an access control system, call PAC on 0161 406 3400.)

Typical components and operation
Most access control systems, in essence, consist of five components as shown in the illustration:

  • 1. The ID device (card, electronic key or PIN code)
  • 2. The reader
  • 3. The door controller
  • 4. The door lock
  • 5. The administration system

The ID device
A user who wishes to gain access through a door or similar physical barrier requires their own ID device (1), and knowledge of a common security code or PIN (personal identification number).

The ID device may be a card or some form of token (electronic key). Each ID device has a unique security code which is detected by the reader. Whether the security code is held within the ID device or memorised by the user, it is entered into the access control system through the reader.

Most of today's state-of-the-art systems can incorporate a wide variety of ID devices. Many types of reading technology are available, including: wiegand, proximity (non-contact), magnetic stripe, infra-red, hands-free, barcode, biometric and smart cards.

Photographs and personnel details can be easily laminated or printed onto ID cards. Magnetic stripes can also be added to offer other functions, such as cashless vending, and smart cards can be used as electronic purses. (ID devices and readers are discussed in more detail in section three).

The reader
The reader (2), which is normally fitted on the wall close to the door handle, detects the unique code either in the ID device or input by the user and sends the code directly to the door controller (3). Several types of reader are available, each suitable for different purposes and environments.

Request to exit
Sometimes a reader is used on both sides of a door, controlling both entry and exit from an area. Normally, however, an RTE switch or button is used to open a door from the secure side. When pressed, this switch (mounted close to the door) sends a signal to the door controller to release the lock for a specified period (Lock Release Time). Anyone can press the switch to open the door when leaving and, therefore, the identity of the person leaving is not recorded.

A request to exit PIR (Passive Infra-Red) switch operates in the same way as a RTE switch but no physical action is required,as the door lock releases automatically when a person approaches the door.

Door controller
The door controller (3) compares the user's code with the information stored in its own database. If the code is valid, the door controller opens the door lock (4) and sends a report of this 'event' to the administration system (5).

The door controller is the heart of the access control system. Its main functions are to:

  • Decide whether a person has access to a particular door at a particular time
  • Provide power to operate the lock
  • Monitor doors for unauthorised access or if a door has been left open
  • Automatically lock and unlock doors at certain times
  • Detect tamper conditions
  • Monitor any inputs that may be configured for extra alarm points
  • Operate programmable relay outputs.

Most networked or remote door controllers have their own copy of the master database stored in the door controller's memory. This is called distributed intelligence and means that the access control system will function normally as per its last update if it loses communication with the master database.

Administering an access control system
The administration system is the means by which the system is commissioned and programmed. It is at this stage that decisions such as who is allowed where and when, and how events are reported, are put into the system.

The system may be administered from a nominated door controller or one or more PCs. Only one door controller is generally required to manage up to four doors. Larger installations require networks of door controllers and a PC to manage more complex systems.

A PC managed system uses specialised access control administration software, which offers more convenience and user friendliness than running the system from a master controller.

Key administration and access information is programmed into the system via the front panel of the door controller or PC. The information entered into the PC or master controller is then downloaded to the local door controllers, which determine whether or not access is granted.

Only the System Administrator has access to the controller or PC software which can be password protected for security. The only components visible to the everyday users of the system are the readers at access points.

Reporting
Event reporting of the movements through controlled doors can be set up in various ways including an alarm on the PC or directly via a printer. Most standalone systems (i.e. without a PC) can be connected to a printer, which will print out the user ID Name (if programmed), the door name/number and the time.

Most standalone door controllers can only store a limited amount of information, but PC administered systems can store unlimited information on disk for analysis at a later time. Important management information can be gleaned from these printed reports, which record the movement of individuals, by door or department.

Access control systems can also report on employee attendance, by integrating the same ID devices within a full Time and Attendance system.

Alarms
Many types of alarm, such as a forced door or smoke, can be reported through the access control system. On standalone controllers, these can be sent directly to a printer. On PC based systems, alarms can be directed to either a printer or PC via an alarm location graphic display, and instruct staff to initiate the appropriate response.

For example, contacts can be placed on fire doors so that the system sends an alarm to the PC, telling the operator when a door has been opened.

The PC based administration system also provides the ability to monitor a whole host of building related equipment, including:

  • Fire doors
  • windows
  • heating
  • ventilation
  • lighting
  • cold storage
  • flooding
  • elevators
  • fencing
  • lone worker protection.