Thursday, June 4, 2009

Access Control Technology Review

Door access control systems have changed over the years. The early units were quite difficult to install. They used simple card readers with all the intelligence located back at the control panel. Over the years more intelligent devices were developed, and now, in the state-of-the-art solutions, most of the intelligence is located at the reader near the door. The latest IP type readers make use of your Ethernet network and are very easy to install. This article reviews the types of systems available and how they can be integrated with IP cameras.

In physical security, the term access control refers to the practice of allowing entrance to a property, a building, or a room only to authorized persons. Physical access control can be achieved by a human (a guard, bouncer, or receptionist), through mechanical means such as locks and keys, or through technological means such as door access control systems that use magnetic locks. In general, in an automated system, access is controlled using a special RFID type proximity card or by keying in an ID number. If the system accepts the person, a relay is activated that unlocks the door.


Basic non-intelligent Readers: The first automated door access control systems utilized simple non-intelligent reader panels that connected back to a central control panel. All the access requests were forwarded back to the central control panel.

Semi-intelligent Readers: The next generation of readers included some intelligence. These readers included enough intelligence to control the door lock hardware, but did not make any access control decisions. The reader simply passed on the code entered to the main controller and then waited for a response. These readers are usually connected to the main panel via an RS-485 bus.

Intelligent Readers: The first intelligent readers connected back to a centralized control panel via the same RS-485 connection as semi-intelligent readers. They included memory and enough intelligence to make access decisions independently of the control panel. The special control panel provides configuration updates and receives events from the readers and maintains a history of the door access.

Intelligent IP Reader and Controller: This is the latest type of reader (such as the
reader from ISONAS). It’s similar to the intelligent reader in that all the decisions are made at the reader, but instead of using a specialized control panel, it uses a standard computer running access control software. It also uses the standard network infrastructure for communication (CAT 5 or 6 cable). Since it totally eliminates any special wiring and specialized control panels, it is the simplest to install and maintain.


The latest door control systems use an IP reader and special software that runs in a Windows computer. The IP reader is attached to the Ethernet network. Magnetic locks and strikes secure the doors which are opened by the IP Reader when the right access card (or other RFID device) passes near the IP Reader. Each Reader contains a list of people who are allowed to enter the door. Software running in a Windows computer is used to control the system, add the people who are allowed to enter the door, send the list to the readers and provide reports of who and when people entered.

IP Reader
An IP based system, such as the one from
ISONAS, utilizes the latest IP readers. It does not require a centralized control panel. Since this system uses network attached components and standard computer systems it provides a very flexible door control system. The reader is powered over Ethernet (PoE) so you don’t require any additional power wires. The reader includes door sense input connections and provides an output that controls the electric door lock.

These readers are designed for both indoor and outdoor use. The optional keypad can be used for additional personnel verification. There are models that use the HID format RFID proximity devices. The devices are available in many different formats from plastic cards, to keychain fobs.

Magnetic Locks and Strikes
There are a variety of automated door locking systems available. You can select either a magnetic lock or electric strike to secure a door.

Magnetic locks are used in high security areas where you need to monitor the movement of people. Since people are required to use their access cards in both directions, you can track who enters and leaves a secure area.

The locking system uses an electromagnetic and armature plate to secure the door. The electromagnet is attached to the door frame while the armature plate is attached to the door. A current passes through the electromagnetic so that it is magnetically attracted to the armature plate holding the door closed. The magnetic strength can provide over 1500 lbs. of holding force. Locks with higher magnetic force can be used to secure an outer door, while lower force locks can be used to secure inner doors.

The locks require special power supplies that can be integrated into a fire panel. It is important to assure that the locks can be released if an emergency situation occurs.

The electric strike are easy to install and are used to secure outer and inner doors, but do not prevent egress from an area like the magnetic lock. It replaces the fixed strike place in a standard lock. 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. To exit from a secured area, the door can be opened by using a knob or level.

To simplify installation, it is important to use locks that require less than 500ma of current. This allows the reader to be powered over Ethernet. The electric locks from Rutherford Controls are examples of this type of low power lock.

Electric strikes generally come in two basic configurations:
  • Fail-secure. Also called Fail-locked or non-fail safe. In this configuration, applying electrical 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 electrical 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.

Adding video to a door control system increases the overall security of the system. By viewing and recording the video, you can keep a visual record of all the people entering your facility as well as determining if the access tag matches the person. You can also catch multiple people entering with only one access (tailgating). Adding additional software will even allow you to do this automatically.

IP camera
By adding an IP camera you can view who enters and leaves an area. The video is captured at the computer running the special NVR software. Cameras from Axis, JVC, IQinvison and others can be used to capture the video.

Adding audio: By using an IP camera that supports audio you can even record the audio at the time of entry. There are many cameras that support audio but you must also select cameras that are also supported by the NVR software. Cameras from Axis and Sony are supported by a number of NVRs and are available with 2-way audio support.

It is important to select access control and the video recording software that are compatible. For example, the Isonas Crystal Matrix software and OnSSI’s NetDVMS software work well together.

The IP reader system notifies the Crystal Matrix Software that a person has opened a door. The Crystal Matrix software then notifies the NetDVMS surveillance software that the door has been accessed causing the NVR software to record the video from the specific camera that is watching the door. Since the video is time stamped you can easily match video to the door access software timeline.

Adding additional Intelligence
There is also optional analytic software available (such as AgentVI) that can automatically watch for tailgating and provide alarms if more than one person tries to enter an area.


As an alternative to an automated system, you can control access by just using an IP camera at each entry door. This works only if you have a centralized security person. Using a camera and intercom, the security person can talk to the person at the door, make a decision based on the picture he sees on his monitor, and then press a lock release button to open the remote door. All communication is done over your Ethernet network so it’s easy to implement.
Here’s what you need to implement the system:

Cameras with Audio
In almost all cases a camera that includes audio, supports MPEG4 compression. This form of compression includes data packets for audio transfer as well as video. picture3For example, the Axis 210A includes two-way audio. It has audio input and audio output so you can attach a microphone and powered speaker. Other cameras with audio include Axis214PTZ and Axis211A.

The intercom and microphone are connected to inputs on the IP camera. All the information from the camera is sent over the standard Ethernet network back to a Windows type PC server.

Doorway Intercoms

picuture7To have a two-way conversation with someone at a doorway requires both a microphone and speaker. The microphone and the speaker must be compatible with the input and output requirements of the camera. It’s best to use a directional microphone to minimize any extra noise in the area. Here’s an example of a two way system that is compatible with most cameras.

Bi-directional Speakerphone. Surface Wall mount speakerphones are designed to interface with various modes of audio/video transmission systems. They provide bi-directional audio with the IP Network cameras that support audio, and video servers with audio support. It contains a built-in electret condenser microphone and a 4" speaker. Also control potentiometers for adjusting the sensitivity of both transmitted and received audio. It can be used outdoors but requires protection from direct exposure to the elements.

NVR IP Software
Special software that runs in your Windows PC computer is used to communicate with the intercom and allows you to view and record the video. For example, NetDVR and NetDVMS from OnSSI provide two-way audio support as well as recording both the video and audio.

These systems are easy to implement but I’m sure you will have questions about all the details. Just contact us at 914-944-3425 or use our contact form to get more information.


Lalitha said...

Thanks for sharing such useful information about access door controls.It's one of the important part of our home security products and also the first thing to be secured is the door with such security systems.

tifany underson said...

A traditional lock would not be enough. If you really want high-level protection, you need these devices.

locksmith in Wichita

Mark pomersbach said...

Yahh...these kind of security system keep us safe.

shalom systems said...

Thank you so much for sharing such an awesome blog...
electro magnetic locks
boom barriers