Buyer Guide: What is a Door Access Control System?

What is a Door Access Control System?


Introduction to Door Access Control

Access control systems provide authorized individuals safe and secure access in and out of various parts of your business while keeping unauthorized people out. They can range from electronic keypads that secure a single door to large networked systems for multiple buildings. Access Systems also greatly simplify management of your facility: no need to replace lost keys, hunt down old keys from terminated employees, or wonder who has access to which areas.

Spend a couple minutes framing the following two questions;

  1. What purpose will your door access control service serve?
  2. What size access system will your business need?


What purpose will your Door Access Control system serve?

To start, determine the purpose the door access control system will serve. The most basic role of an access control system is to keep out anyone who is not authorized and permitted to enter an area. This can be the front door, a parking garage, a server room, a personnel records room, or any other sensitive area. You may also want to use an access control system to track when employees come and go. Another point to consider: how secure do you need the system to be? A basic system usually features a keypad or access card. Higher security applications may require multiple means of authentication (an access card and a thumbprint, for example) and include more redundancy. Finally, consider what other systems need to connect to your access control system. Monitored alarm systems and CCTV systems are two examples.

The diagram in figure 1-A, shows a door access controlled egress assembly. In this single door example, the [1] locking device is an electromagnetic lock (maglock) mounted on the door frame, [2] Entry device is a numeric keypad mounted on the exterior (non-secure) side of the wall, [3] Egress device is a 'Push to Exit' button located on the interior (secure) side of the wall, and [4] Power Supply is the controller, primary power supply and battery back-up power supply. Although not individually labeled, the 4 components are wired together to form a circuit.

Single door magnetic lock egress system diagram.
Figure: 1-A


What size access system will your business need?

Next, once you understand the general role the access control system will serve, think about the number of doors you need to secure. Smaller installations may include just one: a server room with an electronic keypad lock is a common example of a very small access control system. Remember that not every door has to have access control; you can simply leave some locked and only give keys to appropriate personnel. If you plan ahead a little when purchasing your system, you should find it fairly easy to expand later. The smallest systems, designed for one or two doors, are not very expandable, but many four and eight door systems can be linked together when you need to expand.

Once you know the number of doors you will be securing, gather information on each one: the physical makeup and use of your doors will impact the type of locks and entry systems you need. Here are some additional questions to help frame your thinking.

  • Are some doors for customers, and some only for employees?
  • Are the doors wood, steel, or aluminum and glass?
  • Are any designated as fire doors?
  • Do you have any garage doors or parking lot gates to control?
  • Larger installations may include more than one site. An access control system that can be operated over a network lets you manage the security at all your locations from a central point.
  • Another key distinction in access control systems is the difference between free exit and controlled exit systems.
    • Free exit system:, No requirement for leaving a secure area. The system either detects someone approaching an exit (usually through motion sensors) and unlocks the door, or has a release button or bar that allows people to Exit.
    • Controlled exit system:, The system requires the use of the same security for travel in both directions: employees have to enter the code or wave their card to get in or out of the secure area. By law, access control systems have to be set up to allow people to exit if the system fails or power goes out. Controlled exit systems increase both security and your overall costs.



Design your door access control system

There are several components and multiple options to consider when building and designing a security access control system. However, if you keep in mind five basic ingredients, the process is fairly straight forward.

  1. Entry: A way for authorized users to identify themselves and/or unlock the door from the secure side (in a free exit system).
  2. Exit: A way for all users to have free egress from the interior out.
  3. Locking Device: A locking device to secure the door.
  4. System Controller: A controller to manage the interaction between entry devices, egress devices and locking devices.
  5. Functionality: Consider specific requirements for your system (audit tracking, time based opening or doors, battery back-up).

That's it. That is the basic model, for each point of entry or exit, ask yourself; (1) How will I get in?, (2) How will I get out?, (3) What locking device will secure the entry point?, (4) How will the system be controlled? and (5) What other functionality do I need? Applying these questions to each entry point is how the system design process works. If you prefer, give us a call toll free 866.500.5625 and our advisors can design your system and assist in the selection of components and best of all, our project design program is a complimentary service. We are here to help. Now, let's review some of the options related to each of the five ingredients required for a successful door access system design.



Door Access Control Entry Devices: How will I get in?

In all locking systems, the secure lock needs to be released by a physical object (such as a stand-alone lock, Key, Combination or fingerprint) or a combination of any or all. Examples include; Proximity readers, Key switch, Digital Keypads, and biometric readers (fingerprints). These devices are mounted on the exterior (secured side) either on the casing of the door (mullion mount) or on the wall near the door (gang mount). Examples of Entry Device types follow.

  • Stand-Alone (battery powered) Locks as the name implies are an "all-in-one" access control system for a single-door. The lock powered by replaceable internal batteries can be unlocked by keypad, proximity card or a combination. The advantages of stand-alone locks are they can be installed and operational in minutes. The disadvantages of stand-alone locks are they are stand-alone and not part of a broader monitored network. However, some offer hand-held readers that can extract the audit trail from the lock.
  • Stand-alone Lock
    Stand-Alone Lock
  • Proximity readers are the most popular option in commercial access control. They are easy to use, and when cards are lost, it is a simple matter to deactivate them and issue new ones. They can also be combined with photo IDs for additional security. Proximity cards, which can work from one inch to three feet from a sensor, are the most common. Because there is no contact between the card and reader, they are very reliable and suffer little wear and tear. They are also inexpensive. A specialized type of proximity card is the automobile tag, which allows access to a parking facility without requiring the driver to open their window or get out of the car. Automobile tags can work at hundreds of feet away from a sensor. Security access systems can use magnetic stripe or barcode cards, as well, and these can be a money‐saving option if you already use one of these technologies for employee ID cards.
  • Proximity Readers
    Proximity Readers
  • Key Switches offer electronic auditing through a network while continuing to use a physical key to activate the lock.
  • Key Switches
    Key Switches
  • Keypads are common for single door security access and less expensive systems. They are easy to use but less secure, since users have a tendency to write down the entry code or to "lend" it to others. They also do not provide detailed audit trails until you provide unique codes to each individual.
  • Keypads
  • Biometric systems rely on physical characteristics of the users for identification such as fingerprints, handprints, or even retinal scans. They are by far the most secure methods of access control. However, they are also considerably more expensive and can seem invasive to employees forced to use them constantly. Early models proved less unreliable outdoors, so they were not recommended for exterior security access.
  • Biometric Readers
    Biometric Systems
  • Intercom Systems audio door answer and door release systems.
  • Intercom Systems
    Intercom Systems
  • Wireless Entry Systems Receiver and transmitter combinations for remote door release.
  • Wireless Entry Systems
    Wireless Entry Systems



Door Access Control Egress Devices: How will I get out?

To ensure free pass to exit a secure door, all locking systems include a quick exit device. Examples include; push-to-exit buttons, request-to exit bars, motion detectors, emergency (break-glass) exit and Time delayed exit. These buttons are mounted in the interior, on the casing surrounding the door (mullion mount) or on a wall near the door (gang mount). Examples of Egress Device types follow.


  • Push Buttons or Push-To-Exit Buttons As the name implies Push-To-Exit buttons are wall mounted near the exit point and contain directions on a large green or red button. Depressing the button releases the door.
  • Push Buttons
    Push Buttons or Push-To-Exit Buttons
  • Door Push Bars Attach across the inside of the door at the height of the door latch. You exit the door by pressing against the bar. The action of pressing the bar releases the latch and the door opens.
  • Door Push Bars
    Door Push Bars
  • Emergency Exits / Emergency Release Attach on a wall near the exit point. Emergency exits are available has two general types, the first is a 'break-glass' model. To gain exit, you break the glass face. The action depresses a button inside the switch and releases the door. The second type uses a pull down handle to release the door.
  • Emergency Exits / Emergency Release
    Emergency Exits / Emergency Release
  • Motion Sensors Function by detecting a vehicle or person approaching an exit and unlock the door. In addition to motion sensors, several other type of free exit systems are available including: loop detectors and photo cells or beams
  • Motion Sensors
    Motion Sensors
  • Delayed Egress Function by starting a timer once the device is activated. Delayed egress can include voice commands and sounds explaining the door will open in 'x' seconds. For example, once depressed. a delayed egress can count down from 15 seconds to zero and then release the latch opening the door. Delayed egress devices provide the emergency opening functional of a free exit system while providing a delay for enhanced security.
  • Delayed Egress
    Delayed Egress



Door Access Control Locking Devices: How will I Secure the Door?

In all locking systems, the locking device represents the physical security barrier. Locking devices include Magnetic Locks (Maglocks), Electric strikes, Deadbolts, Magnetic Shear Locks and Electrified locksets. These devices are mounted on the door and door casing. Examples of Locking Device types follow. 'Clicking' on any of the device photos will open a new window with direct access to pricing, and product datasheets for further and more detailed reference.


  • Magnetic Locks electromagnetic lock, magnetic lock, or maglock is a locking device that consists of an electromagnet and armature plate. By attaching the electromagnet to the door frame and the armature plate to the door, a current passing through the electromagnet attracts the armature plate holding the door shut. Unlike an electric strike a magnetic lock has no interconnecting parts and is therefore less suitable for super high security applications because it is possible to bypass the lock by disrupting the power supply. Nevertheless, the strength of today's magnetic locks compares well above that of conventional door locks and they cost less than conventional light bulbs to operate. Power supplies incorporating a trickle-charged lead-acid battery pack should be used to retain security for short-term power outages. Magnetic locks possess a number of advantages over conventional locks and electric strikes. For example, their durability and quick operation can make them valuable in a high-traffic office environment where electronic authentication is necessary.
  • Electromagnetic Locks / Maglocks
    Electromagnetic Locks / Maglocks


    • Easy to install: Magnetic locks are generally easier to install than other locks given there are no interconnecting parts.
    • Quick to operate: Magnetic locks unlock instantly when the power is cut allowing for quick operation in comparison to other locks.
    • Suffer less damage: Magnetic locks may also suffer less damage from multiple blows than conventional locks.

    • Requires continuous power: To remain locked, the magnetic lock requires a constant power source. The power drain of the lock is typically around 3 watts, far less than that of a light bulb (conventional around 60 watts or even LED bulbs circa 12 watts), but it may cause security concerns as the device will become unlocked if the power source is disrupted. In comparison, electric strikes can be designed to remain locked should the power source be disrupted. Nevertheless, the requirement for continuous power may actually be preferable in terms of fire safety.


  • Electric Strikes replaces the fixed strike faceplate often used with a latchbar (also known as a keeper). Like a fixed strike, it normally presents a ramped surface to the locking latch allowing the door to close and latch just like a fixed strike would. However, an electric strikes ramped surface can, upon command, pivot out of the way of the latch allowing the door to be pushed open (from the outside) without the latch being retracted (that is, without any operation of the knob) or while excited the knob or lever can be turned to allow egress from the secured area. Electric strikes generally come in two basic configurations:
  • Electric Strikes
    Electric Strikes


    • Fail-secure Also called fail-locked or non-fail safe. In this configuration, applying electric current to the strike will cause it to open. In this configuration, the strike would remain locked in a power failure, but typically the knob can still be used to open the door from the inside for egress from the secure side. These units can be powered by AC which will cause the unit to "buzz", or DC power which will offer silent operation, except for a "click" while the unit releases.

    • Fail-Safe Also called fail-open. In this configuration, applying electric current to the strike will cause it to lock. In this configuration, it operates the same as a magnetic lock would. If there is a power failure, the door would open merely by being pushed/pulled open. Fail safe units are always run using DC power.


  • Electric Deadbolts are recommended for high security interior door and cabinet applications where electromagnetic locks are not required. Electric bolt locks include long life solenoid driven direct throw mortise bolts, some models offer right angle bolts for narrow frames and door stiles and surface mounted bolt locks for door and cabinet applications. Compatible with virtually any access control system, electromechanical bolt locks are available in failsafe and fail secure modes
  • Electric Deadbolts
    Electric Deadbolts


  • Magnetic Shear Locks are recommended to provide superior failsafe holding force and aesthetics for most types of doors, including high profile frameless glass doors. Representing the latest evolution in the development of magnetic locks, shear locks incorporate several features to ensure that the door seamlessly locks and releases without hindrance.
  • Magnetic Shear Locks
    Magnetic Shear Locks


  • Electrified Locksets look and function like a typical cylindrical or mortise style mechanical lock. However, incorporate internal solenoids to enable the lock and latch feature. Building and fire life safety code compliant for fire rated office doors, corridor doors, lobby doors, exit doors and stairwell doors. Whether failsafe or fail secure, controlled access and remote control capability is provided while the door stays latched even when unlocked, maintaining fire door integrity.
  • Electrified Locksets
    Electrified Locksets



Door Access Control Controller and Software: How will I Control the System?

One of the biggest differences between competing access control systems is the computer software used to run them. The software lets you set access levels for each ID and door, view reports, and conduct audits to see who used a door at a certain time. Make sure the software is easy to understand and use: access control systems should decrease administrative headaches, not introduce new ones. Ask for a demonstration of the software and see how easy it is to add new employees, change access levels, create groups, and find detailed reports.

Match the software with your computers operating system carefully: some access control systems only work with specific versions of Windows or other operating systems, so know exactly what OS you are running before finalizing your decision.

Most access control system software is powerful enough to handle the needs of companies up to at least a thousand users. When you start needing to manage multiple shifts, several thousand employees, and hundreds of doors, you drastically increase the overall complexity. At that level, you will likely want ODBC‐ compliant (Open DataBase Connectivity) software that can connect to your existing payroll, time and attendance, and other HR and security systems.

Enclosed is a link to Cobra Controls quick start software guide. Cobra Controls build a high quality graphical interface based on Microsoft .Net. It's a good read and should give you a broad understanding of the functionality available from good quality access control software. Also, Cobra Controls is open source and the actual software is available for download to test. The links are as follows:



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