Posts Tagged ‘ security alarm systems ’

Digital Security System

Friday, November 19th, 2010

A digital security system is any system that integrates digital data for the purpose of creating, sending, or recording information that can be used to protect something. That’s a pretty broad definition, but then again digital security system is a pretty broad phrase.

Since most security alarm systems primarily deal with on/off states (door open/door closed) we could consider them to be inherently digital, but that’s not really what we mean here. What we mean by digital security system is a video security system that operates on the basis of digital data transfer as opposed to an analog system.

For example VHS and Beta video tapes, cassette tape recorders and players, and record albums are all examples of analog devices or media. CDs, DVDs, hard disk drives, and LCD monitors are all examples of digital devices or media.

Older video security systems (often referred to today as “legacy systems”), were strictly analog in nature. The video camera, basically a smaller version of a television studio camera, transferred light energy into electrical energy that could be used to produce a video image. The electrical energy produced by the camera was sent to a Video Tape Recorder (VTR).

The VTR saves the video image as a magnetic recording on magnetic tape. The magnetic recording is in analog form meaning that the signal is recorded with weak spots and strong spots. The analog VTRs used for this purpose are either VHS or Beta format.

The greatest disadvantage of an analog security system is that the analog system is subject to distortion and degradation. Each time the recording is played a slight loss of the signal, especially in the weak spots, is experienced and over time the signal can also deteriorate.

A digital security system or digital video camera initially creates the video image in the same manner as its analog counterpart. However, a digital video camera contains an “analog to digital” converter circuit that transfers the analog signal into a digital signal.

The signals of digital security systems do not have strong and weak points like analog video. The data is only a continuous series of 1s and 0s. This data is sent via a video transmission cable just like the analog video; however instead of using a VTR to record the signal, a Digital Video Recorder or DVR is used. The DVR unit usually contains a highly specialized computer processor called a Digital Signal Processor or DSP the reads the cameras digital data and assembles it into a digital video file that is saved on the DVR.

There are two great advantages of a digital security system as compared to an analog system. First, since digital security systems use digital data, the recording typically doesn’t degrade on magnetic mediums as easy as analog signals do and, the data can be saved to media that doesn’t degrade at all (such as CDs or DVDs). Second, since digital security systems create digital data, the technology and equipment used with personal computers can be integrated for use with the digital security system.

Advances in technology with Integrated Circuit (IC) chips, digital memory storage, use of the Internet, increased speed of computer processors to name of few can all be used to the benefit of a digital security system. For example, miniature IC chips can be used with cameras the size of a pinhole to capture, digitize and transmit video. As computer hard disk drives vastly increase their storage capacity, digital video security systems reap the benefit of longer recording times without rewriting over old data. Faster and broader applications of the Internet allow a user to access their digital system from anywhere in the world there is broadband internet accessibility. And finally, as computer processor speeds and capabilities expand, video quality also gets higher and higher.

Current legacy (analog) security system users don’t despair. Although your systems are typically no longer available for purchase, it is possible to convert them to digital. Thankfully, as the digital revolution has occurred, several devices have been created that help merge some analog devices with digital equipment.

For example, analog security systems can use the internet to monitor their systems like security digital systems can. Users can purchase analog to digital capture cards and servers which transfer the signal from an analog to a digital state and incorporate into files that are computer compatible. For a nominal added expense of these devices, even analog systems can assume some of the advantages of digital security systems.


Wire Free Security Alarm Systems

Monday, October 18th, 2010

If you’re looking for no-hassle security alarms that are easy to install and operate, try using wire free security alarm systems. These security alarm systems detect and notify just like their “wired” counterparts, however the sensors used in these systems do not require a communication wire installed from each sensor to the control panel.

While some security alarm companies insist on professional installation of a wire free security alarm system, they are easy enough to install to be a do-it-yourself project. After all, that’s their biggest advantage. Wire free security alarm systems provide a nice, neat installation, with no need to drill holes in the wall, cut up carpet, or other similar installation headaches.

Other advantages to wire free security alarm systems include the ability to easily add, remove, or relocate alarm sensors. In addition, many systems are designed to include the operation of garage doors, remote appliances, and controlled lighting. Further, wire free security alarm systems’ sensors are versatile; they can be placed just about anywhere and are relatively free from the restrictions that prevent wired sensors from being mounted.

Wire free security alarm systems work just like their “wired” counter parts. That is, sensors are placed around the home or business in key areas or points (also referred to as zones) to detect a variety of actions, changes, or other data. Unusual situations (such as pool temperature or amount of rain water) can be detected by using custom made sensors.

The key behind the versatility in a wire free security alarm system lies with the fact that the sensor can be designed to detect just about anything and the information is sent wirelessly. A standard ‘wired” sensor works by either completing or breaking a circuit loop between the sensor and the master control unit. More complex systems have sensors that do more than just “switching” or “relaying” the circuit; they may also send important data (such as room temperature).

A wire free security alarm system sensor uses the same methods for detection, but instead of being connected to the control panel by a wire, it sends the information to the control panel via radio waves. For this reason, “wired master control panels” usually are not compatible with wire free sensors because the panels lack the radio receiver technology needed to acquire sensors’ signals.

Wire free sensors usually contain their own transmitter and antenna as well as the circuitry to convert the data or signal into a radio signal. The sensor also operates from on-board power in the form of a battery or rechargeable battery (some Lithium ion batteries that can be used in sensors can last up to two years without the need for replacing or charging).
Eliminating the need to drill holes through walls and other structures to run wires is just another benefit of a wire free sensor. In addition, many of these sensors can be installed without drilling a single hole as strong adhesive pads can be used to mount the sensor in place.

Wire Free Security Alarm Systems can also work in power failure conditions if the master control panel has a back-up battery. Most panels have NiMH (Nickel Meal Halide) back-upbatteries that are rechargeable and can furnish continuous power to an alarm system for 12 hours or more. Since the sensors contain their own batteries, no additional power supplies are required in the event of a power outage.

There are two factors regarding a do-it-yourself installation of a wire free alarm system that may be difficult for the amateur installer. First, professional installers have the knowledge and experience of performing numerous installations to be able to determine detection points (areas, regions, or zones). The do-it-your-selfer should be able to determine these areas, but careful study of the entire area to be secured, as well as the proper sensors needed are required. Too many sensors are wasteful and cumbersome to the system, too few could live unprotected areas.

The second factor that could present itself as a challenge is programming the master control panel. Once all of the sensors are installed they need to be linked with the master control panel and the alarm and alert notifications need to be programmed, as well as users and any other automatic settings.

However, these two challenges are also shared by “wired” alarm systems, so in general, installing a wire free security alarm system is no more complicated, in fact it is less so, than install a wired security alarm system.