Authentication in Door Access Control Systems

Door Access Control Systems have been around for many years. Recently new technology has increased security by providing better authentication of the person at the door.  Before selecting your system, you should first determine the degree of security you need.  For example, the security level for an office building could be different from a secure military facility.  There is a tradeoff between cost, ease of use and security level provided.   Key-locks were the original method of controlling the door.  It has been around for thousands of years.  The key provided the authentication.  Since a key can be lost or stolen it is not as secure as using more sophisticated biometric authentication system.  Here is a review of the most common methods for authentication and the level of security they provide.

Keypads

Keypads are probably the least expensive, but also provide the lowest protection.  A PIN number can be forgotten or someone can see the key number entry.  There are two types of keypad systems, one that is included with the lock (sometimes referred to as keyless entry) and another type that includes a separate keypad and electric lock. 

The simple mechanical lock with keypad is primarily designed for home use but can also be used in a small business.  The problem with this system is that it doesn’t have the ability to contain unique numbers so it is difficult to control when there are many people using it.  If someone leaves the organization you have to change the number that everyone else uses. 

The separate keypad is used to control an electric lock on the door.  It is usually used with a central control box that stores an individual code for each person registered in the system.  This system can be used to control access on multiple doors, but it must be used correctly to assure security.  I have seen situations where organizations have issued the same number for everyone.  This type of situation provides very little security.   The database allows you to register each person, and assign the rules about when and where they can enter.  This is more secure but still has problems with stolen numbers and people having to remember the number. 

Card Access Systems

Instead of having each person remember a PIN number, you can provide cards that contain unique codes.  The early readers used bar code, magnetic strip or even Wiegand effect type technology.  

Today most card systems use some type of radio frequency connection and are more secure.  The cards have become credentials that include keyfobs and lanyard style cards and the number is encrypted.   

The latest door access control readers are attached to the network and use standard IP protocols just like computers on the network.  These IP door readers can handle a number of different types of credentials.  The latest “smart cards” not only include unique encrypted numbers but can contain information about the person who holds the credential.  Smart cards such as Mifare type credentials have been used in Europe to pay for transportation.  The credential has built in storage that holds the cash to be used for payment.    

Using credentials is a lot more secure than using a keypad, but there are some concerns about people losing their card or even of higher technology theft of identity using special electronic techniques. 

Security can be increased by adding IP camera systems.  This allows real time and recorded video to be monitored.  

Biometric Authentication

The latest method for authentication is to use a person’s key biometric factors such as fingerprints, voice identification and facial recognition.  This is probably the most secure form of authentication. 

Fingerprint identification:  This has been around for a number of years.  It has become more reliable and less expensive.  You may be familiar with fingerprint identification used by police to catch criminals.  This started out as a manual process but is now automated.  It uses specific characteristics of the fingerprint such as arch, loop and whorl patterns to recognize one print from another.  The same type of identifier is also used in automated access control systems.  Each person is registered in the system using their fingerprints.  The database in the access control system uses the results of the recognition circuits to create a unique pattern for each person.   This pattern can then be compared every time a person uses the system to enter the door. 

There are a number of technologies used to read the fingerprint such as optical, ultrasonic and capacitive.  Each method has pros and cons associated with it.  This system is very secure but there can be problems with reliability.  Dirt and scratches on a finger can deny entry.  

Facial Recognition:  These systems provide an easy way to authenticate a person.  They have gotten much better over the last few years, but there are still some issues with reliability.  For example, if a person comes to the door wearing dark glasses, the system may not be able to recognize them. 

To increase reliability some facial recognition systems have added other biometrics such as Body motion and voice recognition to improve performance.  FST21 Corporation is an example of a multi-modal biometric system that views people as they approach the door.  This provides a much faster analysis and allows people to move quickly through the doorways.  

 It is a challenge for all of us to select the best equipment at the best price.  With that in mind, we continue to review the latest technology from companies all over the world in order to increase our safety and security.   

Please contact us if you need help with your access control systems.  You can contact us at 914-944-3425 or use our contact form.

NVR, DVR, or Video Server?

By Virginia Fair

“Questions………we get questions”

Wasn't that a jingle on a popular TV show of the Sixties? (Seventies?)  Well it could be Kintronics' theme song, too. Our sales engineers get all kinds of questions when fielding calls.

 Today we’ll give you a hypothetical conversation that could occur any day. A caller wants to know what type of video storage device her business should use.

Caller: “What is the difference between a Video Server, a NVR, and a DVR?”

Video Server

Sales Engineer: The network video server is a computer that runs special Video Management Software known as VMS and is used to record video from IP cameras. A windows computer is usually the platform for the VMS, and video is recorded onto the computer’s hard drives in a special video format.

Sometimes people are confused by this term because a number of years back a device that attached an analog camera to the networks was also called a video or camera server. Now that’s known as a Video Encoder.

Caller:  Yes, I was confused by that myself. Now what about the NVR?

NVR

Engineer:  A NetworkVideo Recorder, or NVR, is a complete IP camera recording device. It includes a computer and special Video Management Software. VMS is required for recording video, but it also allows multiple viewers to monitor real time and recorded video.

Caller: I think I understand, but could you go over the differences between the Network Video Server and a Network Video Recorder one more time?

Engineer: Sure. The Video Server and Network Video Recorder are similar in that they both record video. The Network Video Recorder comes with the Video Management Software already installed.

 The Video Server does not include VMS. You select the software you like and load it.

The Video Server usually runs on a Windows operating system and it’s more flexible than the NVR because it is easier to expand and add cameras. The NVR, on the other hand usually has a fixed limit as to the number of cameras it can support.

Caller:  Okay, Got it. Now what about a DVR?

DVR

Engineer: The DVR or Digital Video Recorder is a device that records video from analog cameras to one or more hard drives. The term DVR is also used by the consumer TV market.

 The DVR used in the security market has a fixed number of BNC connections to attach cameras. DVRs are available with 4, 8, 16, 32, and 64 channels, or connections. This means that you have a maximum number of cameras that can be supported by one unit. Once you exceed the number of connections available on that particular DVR, you will need to add another DVR to your system.

 There are some DVRs that can connect to the network, and be viewed using a Windows computer.

Caller: Uh-huh, so what’s difference between a DVR and a NVR?

Engineer: There are several differences but let’s start with these:

• The NVR connects to the computer network along with the IP cameras. So you can take advantage of the existing network infrastructure, meaning you don’t have to run wire from a home base location.
• The DVR uses coaxial connections to each of the analog cameras.
• The NVR supports high resolution megapixel cameras
• The DVR supports only cameras with VGA resolution

Caller: Do they all let me store pictures on my hard disk for later viewing?

Engineer: Always with a NVR, and with the Video Server and DVR, as long as you’re using VMS.  Also, if you’re using VMS on your Windows compute, you can usually distribute the storage across a number of different hard drives on your network. It depends on the VMS.

But no matter which VMS you use, storing images every second, around the clock means storing a lot of pictures that are exactly the same. So you’re using valuable space to no avail. One way around that is to have a motion detector starting and stopping the recording. Another space-saving alternative is to reduce your frame rate.

Caller:  Okay, let’s talk about this software. What do I need?

Engineer:  There are a number of VMS products out there. The main job of any Video Management Software is to record the video from many IP cameras on the network. It is very important to select software that’s reliable and doesn’t crash. Imagine how you’d feel if you lost important video. It’s also important to use a dedicated computer system to run the software.

The various VMS products available have many additional functions, including motion detection, sending special alerts to tell you if something important has happened, flexible displays of real time and recorded video, easy location and display of multiple recorded video channels. The features you choose depend on your particular objectives.

Caller: Do I need a network switch?

Engineer:  Yes. You may have to add a network switch if you don’t have any empty ports on your current switch, or if you don’t have a network switch installed. You require one port for each camera.  It’s best to use a network switch that includes PoE on all ports.

Caller: PoE? What’s that?

Power Over Internet (PoE)

Engineer:  The latest IP cameras get power over the network. This is known as Power over Ethernet or PoE. You can also add a PoE midspan, or a power injector between the switch and the camera.

Using PoE means you only need to run one network cable to each camera. That makes installation so much easier.

Caller: How about a video switch? Will I need that?

Engineer: No. The LAN network switch operates as the switch allowing hundreds of cameras to be viewed on a network.

Caller: Wow, Let me run this past my boss and I’ll get back to you as soon as we figure out which will serve us best.

Engineer: Would it help if I send you some specification pages and data sheets to help with your decision?

Caller. That would be great. Thanks so much for all the information?

Do you have any questions? Do you need clarification for any of the answers here? If so, our sales engineers can provide you with all the answers you need. They can also help you with IP cameras, Door access control, and IP paging systems. Call us at 914-431-1658 or fill out a request information form at http://www.kintronics.com/RequestInfo.htm

Virginia can be reached at virginia@kintronics.com

Viewing Your IP Cameras on Your Smart Phone

Recently there was an article in the IEEE technical journal that declared, “Video Telephony has Finally Arrived”.  They described how the Jetsons first predicted this in 1962, and now we can use our computer and Smartphone to do exactly what George did with his boss Cosmo Spacely.  This animated sitcom described the world in 2062.  I guess we did this sooner than expected. 

To make the video phone a reality a number of obstacles had to be overcome including cost of the video equipment, the cost of high speed connection, and better compression schemes.

Now what about viewing our IP surveillance cameras remotely?  Does the new technology allow us to view all our surveillance cameras at home or on the road?  Well almost.  When we use our Smartphone’s to see each other, we are usually just looking at a person’s face.  If we try to view a wider area, say the complete room, things are not that clear.  The video we see on our Smartphone has less resolution than that usually required for surveillance.  Because we would like to see a lot more detail for our surveillance applications we require much higher resolution and a better display.  A computer is still the best way to view your remote IP cameras.
 
Viewing an IP Camera using your Smartphone
Let’s look at the complete communication channel required to get the video from our cameras to our cell phones or even to a remote computer.  You can picture the components of the system as a set of water pipes connected together.  The bigger the diameter of the pipe the more water can flow.  The smallest diameter pipe will determine how much water flows through the complete system.  There are basically 4 components to the system. 
1)      First is the IP camera.  It needs to compress the video so that it uses as little data as possible to see the video without reducing the resolution. 

2)      Second the outbound bandwidth available at our cellular modem must be high enough to handle the data flow we need.

3)      Third the phone company cellular system must have enough bandwidth.

4)      Finally the Smartphone has to have good enough performance to support the latest cellular services and be able to display the video.

For example, if the bandwidth from the IP camera is 1000 K bits/sec but the cellular network bandwidth is only 200 K bits/sec. the maximum bandwidth through the complete system is limited to 200K bits/sec. 

Compression
The first IP cameras used MJPEG compression, and this is still the best compression for viewing the video on your Smartphone.  Today the new H.264 compression dramatically reduces the bandwidth required for an IP camera.  It reduces the bandwidth and the storage required over a factor of 10X. For example, a VGA camera (running at a frame rate of 20 fps), using MJPEG compression, requires about 4.8 Mbits/sec, while an IP camera using H.264 compression would require less than  400 Kbit/sec.  This compression scheme is dependent on many different factors including the amount of motion detected, so it is possible to use a lot less bandwidth. Take a look at our article about the Latest H.264 Compression for more about this.

Cellular Network
One of the limiting portions of the communication channel is the cellular network.  This is usually the smallest pipe in the system.   3G networks provide a maximum of about 200K bits/sec bandwidth.  Since Smartphones do not work with H.264, there is a lot more bandwidth required for MJPEG.   Since we require 4800 Kbit/sec (using MJPEG compression) to see the video running at 20 fps, we will see a lower frame rate at our Smartphone because of the cellular bandwidth limitation.  In this case, we will get about 1/24 the frame rate or less than 1 fps at the phone.

 4G networks promise to increase the bandwidth to 1 Gbits/sec.  This should allow us to support higher resolution cameras.    I say it should work, but the reality is that cell phone providers need to share bandwidth with all the available users.  They will throttle the bandwidth used by that camera location whenever many people try and use the same tower connection.

Another important aspect of using cellular systems is the cost of the cell service.  You will have to purchase a data package from your local cell phone provider.  There are sometimes limitations to the bandwidth that they will provide.  

Viewing Many Cameras on Your Remote Computer
 When we use a remote computer that’s attached to the internet, there are four things to consider, the compression from the camera, the outbound Internet connection, the Internet speed and the inbound Internet connection.

Many Internet connection companies provide good inbound bandwidth but much less outbound bandwidth so always check.  The outbound Internet bandwidth can dramatically affect the frame rate you can see.  If your provider only gives you an outbound bandwidth of 512K Bits/sec, you will see a much lower frame rate at the remote viewing point. 

The best way to view multiple cameras is to utilize a viewing client that comes with Video Management Software (VMS). This also allows you to view recorded video as well as the real time video.  Ocularis from OnSSi provides an excellent client viewer, while TruViewIP provides a good web client as well as a Smartphone interface.  The bandwidth to the remote viewing client depends on the total number of cameras you are trying to view, so the total bandwidth through the system available becomes very important.  If you have a limited bandwidth at any point in the system, you will see reduced frame rates.

Summary
Some of the same technologies used by our Smartphones to create a video presence are used by our IP camera systems. You can view IP cameras using your Smartphone, but you can’t expect full frame rates because of limited bandwidth through the cellular phone system.  To view recorded video or and view multiple cameras you will need Video Management Software.  You will also need more bandwidth when you view multiple cameras.

If you need help figuring out the best solution for your application, please contact us at 1-800-431-1658 or 914-944-3425 or use our contact form.

A Dear Microsoft Letter

We present a guest blog from one of our IP camera sales engineers, Keaton Baker

Dear Microsoft Windows,


For many many years I've dealt with your issues, bugs, and mysteriousness. I've spent so much time defending your operating system from freezes, incompatibilities, and susceptibility to viruses, spyware, malware, adware and whatever other excuses people come up to to explain your bell curve of reliability.

 I've become desensitized to your lugging around and lackadaisical attitude toward completing simple tasks. I've even tried using Ubuntu to escape your drain on decent computer hardware, but the sense of familiarity quickly brought me back to you. Being an anti-Apple guy, every computer I've had involved seemingly constant re-installs throughout the life of the hardware while trying to maintain the "like new" speed and capability of my computer. If it wasn't you, it was the hard drive or the memory. What did you do!!?

For the last few months, we've been through screen flashing, random freezing for like, 40 seconds every hour or so. Recently you would manage to skip my MP3's and just shut down my computer. When I left this morning, I knew we were in rough shape but I expected you to at least boot up and play music after work.

 I don't think I can handle this anymore, It's over.

 I won't be led on anymore by the hope of the newest updates, service packs, patches, or versions.

It's OK though, I learned a lot about you and became an "expert" in dealing with your idiosyncratic personality.We can still be friends, I'll see you at work all the time but I just took the plunge and brought home a really cool Mac Air with a Solid State Drive so, I don't know... I'm kind of excited. I hope the performance of MAC OS will meet my expectations and stand up to all of the good things I have heard. I turned it on about 2 hours ago and I already have everything I need.

 Nothing confusing or quirky about this...

-- 
Keaton Baker 
Kintronics, Inc. 
500 Executive Blvd 
Ossining, NY 10562
1-800-431-1658 
P: 914-944-3425 X 14 
F: 914-944-0717

If you are interested in information about IP cameras and systems,call Kintronicsat the above numbers or visit our website. www.kintronics.com 

For specific needs please fill out an info request form and a sales engineer willget back to you/

License Plate Recognition, a Twenty-First Century Fact of Life

Article contributed by Virginia Fair

Terrorists were the intended targets for the first license plate readers deployed by New York City.  It was 2006 and the NYPD was involved in what was known as the Lower Manhattan Security Initiative, a counter-terrorism plan that involved setting up movable, random roadblocks in the Financial District. Thousands of cameras provided ancillary surveillance in the area south of Canal Street but the program revolved around special ones equipped with license plate reading technology.

Thank goodness the NYPD has been successful so far in quelling terrorist plots. They have expanded their use of license readers to attack everyday crime wherever it may be happening. According to an article in the New York Times, as of April 2011, New York was using 238 license plate readers. Of these 130 are mobile, mounted on the backs of police cars that might be patrolling any street in the city’s five boroughs. The other 108 are fixed posts at city bridges and tunnels, as well as above other thoroughfares. License plate reading cameras differ from other surveillance IP cameras that monitor broad areas in that they are designed to focus on a small area, and are aimed low to the ground.

 Working with the readers from 2006 to 2011, police tracked down 3,659 stolen vehicles, and issued traffic tickets for 34,969 un-registered ones. In the period from 2010 to 2011 alone, they identified and recovered 248 vehicles bearing stolen license plates.

Divisions dealing with felonies have used the technology to their advantage as well. In 2011 a bank robber was apprehended after high-jacking a livery cab in New Jersey and driving it through the Lincoln tunnel to New York. Somewhere along the route, the license plate was detected and the car traced to a specific block in Queens. FBI agents, alerted by the NYPD, surveyed the block and the next morning apprehended the suspect who had a loaded pistol in his possession. 

In another case of violent crime, a murder suspect was arrested after several cameras spotted his plates in various locations. The police had but to connect the dots to find him sequestered in a closet in a relative’s home. 

How does this work in a city measuring 304.8 square miles (or 468.9 square miles if one counts the 165.6 square miles of water)? The data captured on the cameras are continuously checked against specific databases containing information on stolen vehicles, stolen license plates, and unregistered vehicles. In addition, the cameras’ files are downloaded twice daily to central computers where personnel update the databases each time. Investigators are then able to retrieve new information such as the license plate of a new suspect or the stolen license plate of one they’ve lost track of.

Kintronics just introduced the TruViewLPR, license plate recognition system.  It uses special software developed about 15 years ago with the sole purpose of automatically reading license plates.   The TruViewLPR system can be broken down into four functions:
·         Image collection
·         Image analysis
·         Image and data storage
·         Data transmission

Image Collection
License plate capture cameras with CCD image sensor works with a pulsed infra-red light source to monitor a target area of passing vehicles. The illumination device contains up to 190 LEDs in the near infrared range and is capable of providing a high contrast black and white image similar to the image below.

Notice how the use of infra-red light suppresses most of the surrounding detail and allows the reflective license plate properties to make it dominant in the field.  In addition the TruViewLPR license plate capture camera lets the user alter the contrast by changing each video field up to sixty times per second, on a cycle of three different levels of brightness  - low, medium, and high. Taken together, these allow for optimal plate image processing no matter what the time of day or the condition the license plate in question.

Image Analysis
The captured images are processed by a set of algorithms that extract only the license plate portion of the frame and send it to two different Optical Character Recognition engines for processing.  It takes 200 milliseconds or less for the LPR Software to analyze and come up with an ALPR result. It then reports one of two reads: The read that provides the highest confidence score level of all the captured images for that particular license plate or the read that meets a pre-determined minimum level of confidence

Data Storage
The image with the best results is now saved and linked with the results data. The data might consist of the plate number, the date and time, the lane number.  All this information can be past to compatible Video Management Software such as Ocularis from OnSSi.

Overview Camera
In addition another camera may be used to furnish a scene overview showing a full view of the vehicle which will be linked to the plate data and image, all to be stored to be made available for subsequent  queries. You can also add many IP cameras for multiple overviews when using VMS software such as Ocularis.
 

Data and Image Management and Display
Stored data can be forwarded to a central server over a standard TCP/IP connection or using a wireless connection.

The LPR information can be displayed using Ocularis VMS software or using the Central Management console which will allow an operator to bring up ALPR events based on license plate number, date, time, lane, or other desired characteristics.

Applications
There are a number of applications where automated License plate recognition can be used.  Image collection can take place in a triggered or non-triggered environment.

·         A non-triggered installation needs no detection device. In this mode, software, known as Virtual Vehicle Detector, analyzes each image at a rate of sixty images per second for the presence of a license plate. This image, and additional images containing the vehicle’s license plate data is captured and processed to extract the license plate characteristics

·         A triggered mode requires a detection device and can be used in a number of applications. The trigger could be an in-ground loop or an optical trigger and is called for when several systems are to be tied together to a single event. Such parallel systems might be a vehicle classification system, a transponder system, a parking lot ticket dispenser, a weigh-in motion system , and so on.

The LPR Software device can act as a lane controller, hosting a database that will permit or deny vehicle access into or out of a parking facility, gated community, or high-security compound. This can be done with the optional Universal Interface Controller (UIC) to provide contact closure outputs to open or close a gate or arm in response to queries of the database.

And so in this day and age, a license plate serves as more than just a way to determine if that’s your buddy in the silver Honda up ahead. 

For more information and help with your system design, please contact us at 914-944-3425 or 1-800-431-1658 (in the USA), or you can use our contact form.
 

Door Access Control Review

Door access control systems have been around for many years. The early units used centralized control panels with simple card readers at the doors. To install these systems the readers were wired to a controller and then back to a central control panel. They also required power to be wired to each of the locks usually from a separate control panel.

Over the years more intelligent devices were developed, and now most of the intelligence is located at the reader near the door. The latest IP door readers make use of the Ethernet PoE network and are very easy to install. This article reviews the pros and cons of both systems and compares the cost of installation.

We have used a 6 reader system as an example. Let’s start with the cost comparison. First we looked at the older centralized system with control panel. I’m leaving out the cost for door locks, sensors and Rex buttons because it’s the same in both cases.

Centralized System

Equipment Cost
Cost for the Equipment consists of the readers and the central box with power supply.
Each door requires a door controller and a prox card reader.
6 - Door controllers = $510 x 6 = $3060
6 - Prox readers = 194 x 6 = $1164

The central control box and power supply is required:
1- Site Controller $568
1- Software $768 (This can be a lot higher depending on company)
1- Power supply $495
Total $1831

Grand Total for equipment and software - $ 10,985

Wiring

Traditional 18-2 or composite wiring from the panel to the reader can range from $0.90 to $1.30 per foot. Assuming the 6 readers average 50 feet from the panel at minimum wiring cost will be $270


Installation
Installation is a variable because it depends on the prep work for mounting panel enclosure, distance from the central box, the type of walls and ceilings, and other physical considerations in the building. It goes without saying that multi-building installation adds to the complexity. We used the labor costs at one installation which required about 5 days at about $1000 per day = $5000

Total cost for the system is $16,255.00

IP Reader System
The new all-in-one Isonas door access reader-controller connects right to the network and doesn’t use a central control box. The credential database is entered into a computer running Crystal Matrix software. All this information is downloaded to each of the readers so even if the network goes down, the reader can still control entry.




Equipment cost
Door access control reader-controller $700 x 6 = $4200
Software is free unless you need web based control = $500
8 port network switch with PoE support = $200
Total equipment is $4900

Wiring

Cat 5/6 wiring from the network switch to the reader-controller is about 0.30 per foot. Assuming the 6 doors average 50 feet from the network switch the wiring cost will be $90.00


Installation
Labor cost is again somewhat variable but since there are fewer devices to configure and install at the door physical installation is simplified. As for electrical work, since wiring of the reader-controller to the door strike is contained at the door and PoE supplies power to the lock, we have cut out the need for wiring back to one central point. Thus labor costs are much less. Typically an install requires ½ the time and resources to install so 3 days at $1000 per day is $3000 for labor.

The total system cost is then $7,990.

Summary

Classic System
The classic system has been around for many years so there are many experienced licensed electricians available

IP Reader System
Since the new IP systems use computer networks, a new breed of installers with network and computer expertise is required. The good news is that this can be an in-house self-installation for many organizations that have an IT staff. They have been running the network wire to computers so they have no problem connecting to the same RJ45 connections that are used by computers. The only things they may need help with are installation of the electric locks. In this case they can bring in locksmiths who are familiar with these types of locks. The locksmith installs the electric lock and wires to the pigtail of the reader.

Integration with other systems
Since the IP access control uses the network it's very easy to integrate into an IP camera system. By connecting Intercoms to the IP camera, a remote person can manually release the door. The audio connections go through the camera and find their way back to the safety station that's running Video Management Software. When the call button is pushed on the intercom the safety station is notified by an alarm sound, and the safety officer can see and talk to the person at the door. They can then unlock the door by pushing a button on their computer screen.





Deployment across a Campus
IP systems have another major advantage. They can be deployed anywhere you have a network connection, so if you have multiple buildings connected over a LAN or WAN the IP system can make use of this network and easily communicate to the central control software on a computer in one of the buildings.



Conclusion
Network attached IP door access systems are very easy to install and have excellent flexibility. They can be located across the campus or across the city as long as you have a network connection.

If you need help defining your door access control system, please contact us at 1-800-431-1658 (in the USA) or + 914-944-3425 or use our contact form.

The Lightning's Thief

Contributed by Virginia Fair

Once upon a time a major university installed IP cameras throughout its campus in reaction to a wave of violence perpetrated against female students. All went well until a passing thunderstorm brought a lightning strike which just happened to hit an IP camera mounted on the parapet of a dorm. Of course the camera was destroyed, but have you ever heard the phrase “greased lightning”? It’s a very descriptive term for within seconds, the surge created by the lightning traveled through the network destroying both the server and the switch, creating havoc right down to the network cards in students’ laptops at the end of the cable runs.

Was there any collateral damage? Only if you count the building’s entire IT backbone, including the surveillance system which went down; in monetary terms, over $100,000. But beyond money, the greater loss was the female students’ sense of security. Without the cameras and network recorders they were left vulnerable until replacements could be secured.

How could this be? Was it possible that no one in the affected building had a surge protector in place? They probably did, but calling a lightning strike a power surge is like calling a tsunami a hot tub. It’s been said that lightning never strikes twice but the university was taking no chances. That’s when they realized the need for specialized surge protection. They could then protect their servers, IP cameras, and networks. But first things first, let’s start with a coup le of definitions

Volt
Voltage is a measure of this difference of potential electrical energy. Just as water flows out of a hose because there’s higher pressure at the faucet than at its other end, electric current flows from place to place due to an imbalance. One end of a wire has greater electric potential energy than the other, so, electric current flows from one end to the other.

Power surge
A surge in power occurs whenever the voltage exceeds the designated level, which in the USA is 120 volts and in Europe 240 volts.

Transient Voltage Surge Protectors
A transient voltage surge protector fits between the AC outlet and the equipment it is protecting. These are available with a single outlet or with a number of outlets like a power strip. There are also surge protectors that protect the network, including some that are designed specifically for IP cameras that use PoE.

Most surge protectors have a component called a metal oxide varistor or MOV which connects the hot power line to the outlet’s grounding wire so it can divert excessive voltage away from the device it is protecting. The MOV consists of three parts: a piece of metal oxide in the middle and two semiconductors. The semiconductors connect the hot power wire to the grounding line. The semiconductors have what is called variable resistance that see-saws in depending on the electric current. If the voltage flows below an optimum level, the semiconductors maintain a high resistance, keeping it in the circuit, if it rises above that level, the semiconductors adjust, drops to a lower resistance that dumps the excessive current to ground. If the voltage is correct, the MOV does nothing at all. Surge protectors such as those from Ditek have two modes of operation. In the first, it dumps power to ground. The second kicks in when the power is very high. It then will sacrifice itself by shorting to ground and burning out like a fuse.

Most transient voltage surges are the result of a boost of electrical charge anywhere in the power lines, increasing the electrical potential energy, which in turn increases the flow of current to your wall outlet. The usual suspects are voracious power hogs like air conditioners, elevators, and refrigerators that gobble up a lot of energy when their compressors and motors cycle on and off. Such brief sudden demands for power can upset the voltage flow in the system. Other surges can be attributed to downed power lines, faulty wiring or utility company’s equipment failures. In today’s world, where electricity flows from power plants through a complicated maze of lines, transformers, and more lines to our home and office walls, the possible points of failure are myriad, and any glitch can cause an uneven power flow. So installing a surge protector isn’t a case of preparing for if it’s preparing for when.

The diagram above shows an example of a network system with IP cameras that is protected by various surge devices. More or less surge protectors can be added depending on the environment. One precautionary warning though, is lightning. We travel a slippery slope when it comes to a lightning strike. A direct lightning hit to the wire or device itself will not only fry them but will take out the surge protector, but lightning that strikes nearby causes a surge that can usually be controlled by a surge protector.

Need help with protecting your equipment? We carry a full line of Ditek Gigabit capable protectors. Models range from theMRJPOE, meant for single inputs and protect power, data, and video on up to The DTK-RM16C5 with a 16 port protected panel which can protect a variety of network gear. Also available are 12 port panels compatible with PoE current requirements, and single protectors to protect up to 8 megapixel IP video.

Call us - before lightning strikes. We can be reached at 800-431-1658, 914-944-3425 (outside the USA) or just use our contact form.