Monday, July 20, 2015

Design of CCTV System

CCTV system design
Designing a CCTV system is a complex task, requiring at least basic knowledge of all the stages in a system, as well as its components. But more importantly, prior to designing the system, we need to know what the customer expects from it.

Understanding the customer’s requirements
The first and most important preparation before commencing the design is to know and understand the customer’s requirements. Customers can be technically oriented people, and many understand CCTV as well as you do, but most often they are not aware of the latest technical developments and capabilities of each component.
The most important thing to understand is the general concept of the surveillance the customer wants, Constant monitoring of cameras and activities undertaken by 24-hour security personnel, or perhaps just an unattended operation (usually with constant recording), or maybe a mixture of the two. Once you understand their general requirements, it might be a good idea to explain to them what is achievable with the equipment you would be suggesting. This is reasonably easy to accomplish with smaller and simpler systems, but once they grow to a size of more than 10 cameras some of which could be PTZs, a few monitors, more than one control point, a number of alarms, VCRs, and the like, things will get tougher.

Many unknown variables need to be considered: What happens if a number of alarms go off simultaneously? Which monitor should display the alarms? Will the alarms be recorded if the DVR/VCR(s) is/are playing back? What is the level of priority for each operator? And so on.

Those are the variables that define the system complexity and as in mathematics, in order to solve a system with more variables, one needs to know more parameters. They can be specified by the customer, but only after the customer has understood the technical capabilities of the equipment.

Understandably, it is imperative for you, as a CCTV expert, to know the components, hardware, and software you would be offering and to achieve what is required in the best possible way. You can create a favorable impression in the customer’s mind if at the end you give him or her as much as, or even more than, what you have promised. You will prove unsatisfactory if you do not. Remember that if the customer is fully satisfied the first time, chances are he or she will come back to do business with you again. To put it simply: Do not claim the system will do this and that if you are not certain; make sure your system delivers what you say it will.

So, to design a good, functional system, one has to know the components used, their benefits and limitations, how they interconnect, and how the customer wants them to be used. The first few parts are assumed to be fulfilled, since you would not be doing that job unless you knew a few things about CCTV. The last one – what the customer wants – can be determined during the first phone call or meeting.

Usually, the next step is to conduct a site inspection. Here is a short list of questions you should ask your customer prior to designing the system and before or during the site inspection:

• What is the main purpose of the CCTV system?
If it is a deterrent, you need to plan for cameras and monitors that will be displayed to the public.
If it is a concealed surveillance, you will need to pay special attention to the camera type and size, its protection, concealed cabling, and the like, as well as when it is supposed to be installed (after hours perhaps).

• Who will be the operator(s) ?
If a dedicated 24 hour guard is going to use the system, the alarm response needs to be different from that expected when unattended, or a partially attended, system operation.

• Will it be a monochrome or color system ?
The answer to this question will dictate the price, as well as the minimum illumination response.
Consequently, the lighting in the area needs to be looked at. A color picture will give more details about the observed events, but if the intention is to see images in very low light levels, or with infrared lights, there is no other alternative but B/W cameras (unless the customer is prepared to pay for some of the new cameras available on the market that switch between color and monochrome operation).
The price of a color system is dictated not only by the cameras, but also by the monitors, multiplexers, and/or quads (if any). Needless to say, sequential or matrix switchers, as well as time-lapse VCRs, are the same for both B/W and color.

• How many cameras are to be used ?
A small system with up to half a dozen cameras can be easily handled by a switcher or multiplexer, but bigger systems usually need a matrix switcher or a larger number of switchers and multiplexers.

• How many of the cameras will be fixed focal length and how many PTZ ?
There is a big difference in price between the two because if a PTZ camera is used instead of a fixed one, the extra cost is in the zoom lens (as opposed to the fixed one), the pan and tilt head or dome, the site driver, and the control keyboard to control it. But the advantages your customer will get having a PTZ camera will be quadrupled. If on top of this, preset positioning PTZ cameras are used, the system flexibility and efficiency will be too great to be compared with the fixed camera system. A system with only one PTZ camera and half a dozen fixed ones is a choice that may require a matrix switcher for control and will increase the price dramatically (compared to a system with only fixed cameras). Alternatively, single PTZ camera control can be achieved via a special single-camera digital or hard-wired controller, but they would also increase the price considerably. So, if a PTZ camera is required, it would be more economical to have more than one PTZ camera.

• How many monitors and control keyboards are required?
If it is a small system, one monitor and keyboard is the logical proposal, but once you get more operators and/or channels to control and view simultaneously, it becomes harder to plan a practical and efficient system. Then, an inspection of the control room is necessary in order to plan the equipment layout and interconnection.

• Will the system be used for live monitoring (which will require an instant response to alarms), or perhaps recording of the signals for later review and verification ?
This question will define whether you need to use DVR/VCR(s) with multiplexer(s). If you have a matrix switcher, you will still need a multiplexer or two in addition. Have in mind that the time lapse mode you are going to use depends on how often the tapes can be changed, and this defines the update rate of each camera recorded. Choose, whenever possible, a pair of 9-way (or 8-way) multiplexers instead of one 16-way, if you want to minimize the time delay in the recording rate update.

• What transmission media can be used on the premises ?
Usually, a coaxial cable is taken as an unwritten rule and installation should be planned accordingly. Sometimes, however, there is no choice but to use a wireless microwave or even a fiber optics transmission, which will add considerably to the total price. If the premises are subject to regular
lightning activity, you had better propose fiber optics from the beginning and explain to the customer the savings in the long run. So, you have to find out more about the environment in which the system is going, what is physically possible and what is not, and then plan an adequate video and data transmission media.

• Lastly and probably the most important thing to find out, if possible, is what sort of budget is planned for such a CCTV system?
This question will define and clarify some of the previous queries and will force you to narrow down either the type of equipment, the number of cameras, or how the system is expected to work. Although this is one of the most important factors, it should not force you to downgrade the system to something that you know will not operate satisfactorily.
If the budget cannot allow for the desired system, it is still good to go back to the customer with a system proposal that you are convinced will work as per his or her requirements (even if it is over budget) and another one designed within the budget with as many features as the budget will allow for. This will usually force you to narrow down the number of cameras, or change some from PTZ to fixed. The strongest argument you should put forward when suggesting your design is that a CCTV system should be a secure one, which can only be the case if it is done properly. Thus, by having a well-designed system, bigger savings will be made in the long run.

By presenting a fair and detailed explanation of how you think the system should work, the customer will usually accept the proposal.

Site inspections
After the initial conversation with the customer and assuming you have a reasonably good idea of what is desired, you have to make a site inspection where you would usually collect the following information:
• Cameras: type (i.e., B/W or color, fixed or PTZ, Resolution, etc.).
• Lenses: angles of view, zoom magnification ratio for zoom lenses (12.5–75 mm, 8–80 mm, etc.).
• Camera protection: housing type (standard, weatherproof, dome, discrete, etc.) mounting.
• Light: levels, light sources in use (especially when color cameras are to be used), east/west viewing direction. Visualize the sun’s position during various days of the year, both summer and winter. This will be very important for overall picture quality.
• Video receiving equipment: location, control room area, physical space, and the console.
• Monitors: Resolution, size, position, mounting, and the like.
• Power supply: type, size (always consider more amperes than what are required). Is there a need for an uninterruptable power supply (UPS)? (VA rating in that case).
• If pan/tilt heads are to be used: type, size, load rating, control (two wire – digital or multi-core). Is there a need for preset positioning (highly recommended for bigger systems)? Where are they going to be mounted? What type of brackets ?
• Make a rough sketch of the area, with the approximate initial suggestions for the camera positions. Take into account, as much as possible, the installer’s point of view. A small change in the camera’s position, which will not affect the camera’s customer. An unwritten golden rule for a good picture is to try and keep the camera from directly facing light.
• Put down the reference names of areas where the customer wants (or where you have suggested) the cameras to be installed. Also write down the reference names of areas to be monitored because you will need them in your documentation as reference points. Be alert for obvious “no-nos” (in respect to installation), even if the customer wishes something to be done. Sometimes small changes may result in high installation costs or technical difficulties that would be impossible to solve. It is always easier to deter the customer from making changes by explaining why in the initial stage, rather than having to do so later in the course of installation, when additional costs will be unavoidable.
To know more just read Condensed Code BS EN 62676-4 and BS EN 50132-7, BS EN 62676-4 Clause 4.4 & BS EN 62676-4 Clause 4.5.

Designing and quoting a CCTV system
With all of the above information, as well as the product knowledge (which needs constant updating), you need to sit down and think.

Designing a system, like designing anything new, is a form of art. As is true of many artists, your work may not be rewarded immediately, or it may not be accepted for some reason. But think positively and concentrate as if that is to be the best system you can propose. With a little bit of luck you may make it the best, and tomorrow you can proudly show it to your colleagues and customers. Different people will use different methods when designing a system. There is, however, an easy and logical beginning.

Always start with a hand drawing of what you think the system should feature. Draw the monitors, cameras, housings, interconnecting cables, power supplies, and so on. While drawing you will see the physical interconnection and component requirements. Then you will not omit any of the little things
that can sometimes be forgotten, such as camera brackets, types of cable used, and cable length. Making even a rough hand sketch will bring you to some corrections, improvements, or perhaps further inquiries to the customer. You may, for example, have forgotten to check what the maximum distance for the PTZ control is, or how far the operators are to be from the central video processing equipment, power cable distances, voltage drops, and so on.

Once you have made the final hand drawing, you will know what equipment is required, and it is at this point that you can make a listing of the proposed equipment. Then, perhaps, you will come to
the stage of matching camera/lens combinations. Make sure that they will fit in the housings or domes you intend to use. This is another chance to glance through the supplier’s specifications booklet. Do not forget to take into account some trivial things that may make installation difficult, like the coaxial cable space behind the camera (remember, it is always good to have at least 50 mm for BNC terminations), the focusing movement of a zoom lens (as mentioned earlier in the chapter on zoom lenses, in a lot of zoom lenses focusing near makes the front optical element protrude for an additional couple of millimeters), and so on.


The next stage is pricing the equipment – costs, sales tax and duty, installation costs, profit margins and the most important of all (especially for the customer) the total price.

Do not forget to include commissioning costs in there, although a lot of people break that up and show the commissioning figure separately. This is more of a practical matter, since the commissioning cost may vary considerably and it could take longer or shorter than planned. General practical experience shows that it will always take at least three times longer than planned. Also, in the commissioning fees, time should be allocated for the CCTV operator’s training.

After this step has been completed, you need to make a final and more accurate drawing of the system you are proposing. This can be hand drawn, but most CCTV designers these days use computers and CAD programs. It is easier and quicker (once you get used to it), and it looks better.
Also, the hand-calculated price needs to be written in a quotation form, with a basic explanation of how the system will work and what it will achieve. It is important for this to be written in a concise and simple, yet precise form, because quotations and proposals (besides being read by security managers and technical people) are also read by nontechnical people such as purchasing officers and accountants.

Often, spreadsheet programs are used for the purpose of precise calculation, and this is another chance to double-check the equipment listing with your drawing and make sure nothing has been left out. As with any quotation, it is more professional to have a set of brochures enclosed for the components you are proposing.

In the quotation, you should not forget to include your company’s terms and conditions of sale which will protect your legal position.

If the quotation is a response to a tender invitation, you will most likely need to submit a statement of compliance.

This is where you confirm whether your equipment complies or does not comply with the tender requirements. This is where you also have to highlight eventual extra benefits and features your equipment offers. In the tender, you may also be asked to commit yourself to the progress of the work and supply work insurance cover, in which case you will need a little bit of help from your accountant and/or legal advisor.


Many specialized companies only design and supply CCTV equipment, in which case you will need to get a quote from a specialized installer, who, understandably, will need to inspect the site. It is a good practice, at the end, to have all the text, drawings, and brochures bound in a single document, in a few copies, so as to be practical and efficient for reviewing and discussions.

Installation considerations
If you are a CCTV system designer, you do not have to worry about how certain cables will be pulled through a ceiling, raisers, or camera pole mounting; that is the installer’s job. But it would be very helpful and will save a lot of money, if you have some knowledge in that area. If nothing else, it is a good practice, before you prepare the final quotation, to take your preferred installer on site, so that you can take into account his or her comments and suggestions of how the practical installation should be carried out.

First, the most important thing to consider is the type of cable to be used for video, power, and data transmission, their distances and protection from mechanical damage, electromagnetic radiation, ultraviolet protection, rain, salty air, and the like. For this purpose it is handy to know the surrounding area, especially if you have powerful electrical machinery next door, which consumes a lot of current and could possibly affect the video and control signals. Powerful electric motors that start and stop often may produce a very strong electromagnetic field and may even affect the phase stability of the mains. This in turn will affect the camera synchronization (if line-locked cameras are used) as well as the monitor’s picture display.

For example, there might be a radio antenna installed in the vicinity, whose radiation harmonics may influence the highfrequency signals your CCTV system uses.
Mounting considerations are also important at both the camera and monitor end. If poles are to be installed, not only the height, but also the elasticity of the poles is important. Steel poles, for example, are much more elastic than concrete poles. If a PTZ camera is installed, the zoom lens magnification factor will also magnify the pole’s movement which could result from wind, or vibrations from the pan/tilt head movement itself. This magnification factor is the same as the optical magnification (i.e., a zoom lens, when fully zoomed in, may magnify a 1mm movement of the camera due to wind to a 1 m variation at the object plane).
The shape of the pole is also very important
– hexagonal poles are less elastic than round ones of the same height and diameter.
The same logic applies to camera and pan/tilt head mounting brackets. A very cheap bracket of a bad design can cause an unstable and oscillating picture from even the best camera.
If the system needs to be installed in a prestigious hotel or shopping center, the aesthetics are an additional factor to determine the type of brackets and mounting. It is especially important then not to have any cables hanging.

The monitoring end demands attention to all aspects. It needs to be durable (people will be working with the equipment day and night), or aesthetical (it should look good) and practical (easy to see pictures, without getting tired of too much noise and flashing screens).
Since all of the cables used in a system wind up at the monitoring end and in most cases this is the same room where the equipment is located, special attention needs to be paid to cable arrangement and protection.

Often, cables lying around on the floor for a few days (during the installation) are subject to people walking on them, which is enough weight to damage the cable characteristics, especially the coaxial cable impedance. Remember, the impedance depends on the physical relation between the center core, the insulation, and the shield. If a bigger system is in question, it is always a better idea to propose a raised floor, where all the cables are installed freely below the raised floor.
Sometimes, if a raised floor is not possible, many cables can be run over a false ceiling. In such cases special care should be taken to secure the cables as they could become very heavy when bundled together.

Larger installations may want a patch panel for the video signals.
This is usually housed in a 19'' rack cabinet, and its purpose is to break the cables with special coax link connectors so as to be able to reroute them in case of a problem or testing.
Many installers fail to get into the habit of marking the cables properly. Most of them would know all of the cables at the time of installation, but two days later they can easily forget them. Cable marking is especially critical with larger and more complex systems. Insist on proper and permanent cable markings as per your drawings. There are plenty of special cable-marking systems on the market. In addition, listing of all the numbers used on the cables should be prepared and added to the system drawings.

Remember, good installers differ from bad ones in the way they terminate, run, arrange, and mark the cables, as well as how they document their work.

Drawings
There is no standard for drawing CCTV system block diagrams, as there is in electronics or architecture. Any clear drawing should be acceptable as long as you have clearly shown the equipment used (i.e., cameras, monitors, VCRs) and their interconnection.
Many people use technical drawing aids, such as CAD programs, or other PC or Mac-based drawing packages. Depending on the system size, it might be necessary to have two different types of drawings: one of a CCTV block diagram showing the CCTV components’ interconnection and cabling requirements, while the other could be a site layout with the camera positions and coverage area. In smaller installations, just a block diagram may be sufficient.
The CCTV block diagram needs to show the system in its completeness, how the components are interconnected, which part goes where, what type of cable is used, and where it is used.
If the site layout drawing is well prepared, it can later be used as a reference by the installer, as well as by your customer and yourself when reviewing camera locations, reference names, and discussing eventual changes.
When the CCTV system is installed and the job is finished, drawings may need small alterations, depending on the changes made during the installation. After the installation, the drawings are usually enclosed with the final documentation, which should also include manuals, brochures, and other relevant documentation.


Commissioning
Commissioning is the last and most important procedure in a CCTV system design before handing it over to the customer. It involves great knowledge and understanding of both the customer’s requirements and the system’s possibilities. Quite often, CCTV equipment programming and setup are also part of this. It includes video matrix switcher programming, time-lapse VCR programming, camera setup, and so on.
Commissioning is usually conducted in close cooperation with the customer’s system manager and/or operator(s), since a lot of settings and details are made to suit their work environment.
The following is a typical list of what is usually checked when commissioning:
All wiring is correctly terminated.
Supply voltage is correct to all appropriate parts of the system.
Camera type and lens fitted are correct for each position.
Operation of auto irises under various light levels is satisfactory.
If VCRs are fitted, they should be recording in the most efficient time-lapse mode (especially when multiplexed cameras are being recorded).
If DVRs are installed, the pictures per second performance and image quality (compression setting) should be checked .
All system controls are properly functioning (pan/tilt, zoom, focus, etc.)
The setting of all pan and tilt limits is correct.
Preset positioning, if such cameras are used, is correct.
The level of supplementary lighting is satisfactory.
The system must continue to work when the main supply is disconnected, and a check should be made as to how long it does (if UPS is used).
Commissioning larger systems may take a bit longer than the smaller ones. This is an evolution from the system on paper to the real thing, where a lot of small and unplanned things may come up because of new variations in the system concept. Customers, or users, can suggest the way they want things to be done, only when they see the initial system appearance. Commissioning in such cases may therefore take up to a few days.
Commissioning under  BS EN 62676-4 Clause 4.6 & BS EN 62676-4 Clause 13.

Training and manuals
After the initial setup, programming, and commissioning are finished, the operators, or system users, will need some form of training.
For smaller systems this is fairly straightforward and simple. Just a verbal explanation may be sufficient, although every customer deserves a written user’s manual. This can be as simple as a laminated sheet of paper with clearly written instructions.

Every piece of equipment should come with its own User’s Manual, be it a time lapse VCR, a camera, or a switcher, but they have to be put together in a system with all their interconnections and this is what has to be shown to the customer. Every detail should be covered, especially alarm response and the system’s handling in such cases. This is perhaps the most important piece of information to the operators.

For larger systems, it is a good idea to bind all the component manuals, together with the system drawings, wiring details, and operator’s instructions, in a separate folder or a binder. Naturally, for systems of a larger size, training can be a more complex task. It may even require some special presentation with slides and drawings so as to cover all the major aspects.

Good systems are recognized not only by their functionality but also by their documentation.

Handing over
When all is finished and the customer is comfortable with what he or she is getting, it is time to hand over the system. This is an official acceptance of the system as demonstrated and is usually backed by the signing of appropriate documents.
It is at this point in time that the job can be considered finished and the warranty begins to be effective.
From now on, the customer takes over responsibility for the system’s integrity and operation.
If customers are happy with the job, they usually write an official note of thanks. This may be used later, together with your other similar letters, as a reference for future customers.
Documentation consider BS EN 62676-4 Clause 4.8, BS EN 62676-4 Clause 15.3 & BS EN 62676-4 Clause 16.

Preventative maintenance
Effective and regular maintenance of a CCTV surveillance system is essential to ensure that the system remains reliable at all times. It is advisable that maintenance of the CCTV system should be carried out by the company which installed the system. However, the maintenance company should have the means, including necessary spare parts and documentation, to meet the recommendations given here.
Note: This recommendation does not place an obligation upon customers who purchase their systems to have them maintained by the installing company. Maintenance is a matter of agreement between the customer and the installing company or a separate maintenance company. Maintenance comes under BS EN 62676-4 Clause 17 & SC CoP Guiding Principle 10.

The preservation of security within the maintenance company is of paramount importance and steps should be taken to ensure the safe keeping of all customers’ equipment and documentation relating to a particular installation/contract.

Note: BS EN 50132-7 states that “CCTV systems should be maintained in accordance with the schedule supplied by the system designer or supplier”, but does not detail any specific maintenance requirements. These guidelines give specific advice for the maintenance of CCTV surveillance systems, and provide examples of the type of documentation required to be used by the service company.

A maintenance company should ensure that adequate vetting of all employees is carried out. All employees, who visit a customer’s premises, shall carry identification cards which should include a photograph and signature of the bearer, the company’s name, contact details and a date of expiry (maximum of 3 years).
Each service technician employed by the maintenance company should carry a range of tools, test equipment and other equipment to enable them to perform their functions satisfactorily. Specialist tools, test equipment and plant should be available for deeper investigation if necessary.
Note: Disconnections, for whatever reason, should be recorded on a maintenance record and authorised by the client or his representative.
The maintenance company’s organisation should be so staffed as to ensure that the recommendations of this Code of Practice can be met at all times. The following factors should be taken into consideration:
1.       the number of installations to be serviced
2.       the complexity of the installations;
3.       the geographical spread of the installations in relation to the location of the maintenance company, its branches and its service personnel
4.       the method of calling out service personnel outside normal office hours, where applicable.
5.       Service personnel should be adequately trained and training should be updated whenever appropriate.
Maintenance Service is 3 types but scope of work is same.
A.   Preventive Maintenance service.
B.   Corrective Maintenance service.
C.   Performance Maintenance service.

http://arindamcctvaccesscontrol.blogspot.in/2014/09/service-and-maintenance-for-cctv.html


Note: The BS EN standards BS EN 62676-2-X comprising part 1, 2 and 3, provide detailed guidelines to manufacturers as to how they should implement IP video transmission products.

An end user is unlikely to benefit by reading the 62676-2-X standards. They may instead be involved in a buying decision which could place reliance on claims of conformance to the part of the BS EN standard the manufacturer chose to implement. Interoperability of equipment is not solely reliant on the requirements included in the BS EN standards in their current form. There is no guarantee that a product which simply claims BS EN 62676 compliance will provide full compatibility with another claiming the same compliance although it should allow for a minimum level of image transfer. 

Installers, users and specifiers should treat claims of interoperability between manufacturers products with caution. The parts of the BS EN standard which focus on interoperability, are 62676-2-2, which describes the PSIA guidelines for interoperability of IP Video devices, and 62676-2-3, which describes the ONVIF guidelines for interoperability.

ONVIF and PSIA, are at their base level, a common set of commands allowing basic communication between devices but this does not guarantee that the devices will function to the full potential of their design. Issues with product firmware and software should also be considered: a change of firmware / software versions should be tested separately to ensure continued interoperability. Whilst the specifications try to take this into account, the number of products claiming to be conformant currently makes this an impossible task.

Claims by product manufacturers that PSIA or ONVIF compliance means that users do not have to check that the products work together should be treated with great caution. It is strongly recommended that all such products are tested before being deployed.

Saturday, July 18, 2015

Difference between 1080p and 2160p

Difference between 1080p and 2160p 

1080p

1080p (aka Full HD/ FHD and BT.709) is a set of HDTV high-definition video modes characterized by 1080 horizontal lines of vertical resolution and progressive scan(p), as opposed to interlaced, as is the case with the 1080i display standard. The term usually assumes a Wide screen aspect ratio of 16:9, implying a resolution of 1920x1080 (2.1megapixel) often marketed as Full HD.



2160p
2160p is an alternative name for 4K UHD, a resolution supported by UHDTV products and which offers four times the definition of 1080p. The number 2160 stands for a display resolution which has 2160 pixels along the shortest side, while the letter p stands for progressive scan or non-interlaced. In a progressive image, the lines of resolution of the image go from the top of the screen to the bottom. The only planned higher definition format for television is 8K UHD.

Saturday, July 4, 2015

Fiber cabling with PoE for long-distance IP camera installation

Fiber optic cabling with PoE converters allows long-distance IP camera placement

Power over Ethernet (PoE) technology enables powering IP surveillance cameras through the transfer of DC electrical power along with data over standard unshielded twisted pair (UTP) cabling. This cabling connects to a network device through an RJ-45 port that injects the power from power sourcing equipment such as a PoE switch or midspan PoE injector. PoE provides a flexible and convenient means of powering devices that are located in out-of-the-way locations, and saves money by eliminating the expense and difficulty of direct electrical wiring. A challenge with PoE is reaching remote locations outside the distance limitation of UTP cabling. According to the TIA/EIA 568-5-A standard for category 5e cable, the maximum length for a cable segment is 100 meters (328 ft), and PoE power injectors or midspans do not increase the distance of the data link.

So, how do you get beyond that 100-meter limit? Once answer is through fiber optics. Fiber optic cabling is an effective method to overcome the distance and bandwidth limitations of UTP, and media converters are a commonly used to integrate copper network equipment and fiber. Since DC power cannot be conducted over fiber, PoE media converters are the solution to extend network distances via fiber to remote IP cameras. A PoE media converter converts the fiber to copper, and sends DC power to the camera over the UTP cabling.
How PoE Media Converters Work
On the main article image/PoE schematic that appears at right, an Ethernet switch with RJ-45 ports resides in a control room or data closet. The copper UTP cabling is converted to fiber with a standard media converter. The fiber is run a long distance to the PoE media converter located near a convenient AC or DC power source, where it converts the fiber back to copper UTP. The PoE media converter also functions as a power-sourcing mini switch, and injects PoE (DC power) over the UTP cable. At the other end of the UTP cable is the IP camera, located up to 100 meters away from the PoE media converter.

PoE media converters are available with Gigabit Ethernet and Fast Ethernet data rates and can support PoE (15.4 watts) or PoE+ (25.5 watts). PoE media converters function like PoE mini-switches, and are available in a variety of multi-port configurations, including dual RJ-45 and dual fiber ports. They can support fixed fiber connectors or small form pluggable transceivers.

To understand those power specifications, it’s worth knowing that in 2003, the IEEE ratified the 802.3af PoE Standard. That standard provides up to 15.4 watts of power per port. Late in 2009, the IEEE ratified the 802.3at PoE Standard known as PoE+ that provides up to 25.5 watts of power for each port. PoE+ can be required to power IP cameras with Pan-Tilt-Zoom (PTZ) capabilities, and weather-hardened cameras used in cold environments.
Key Features to Consider When Selecting a PoE Media Converter:
• PoE+ to future proof applications
• Out-of-the-box support for IEEE Alternative A and B, and Legacy Power detection
options (without the need for jumper wires or external cables)
• Jumbo Ethernet Frames to enhance throughput for reliable data flow
• Multiple port configurations for deploying a variety of architectures and topologies:
– Daisy chain media converters or install in ring topology
– Redundant fiber with less than 50ms switch over time
– Dual UTP ports for powering two PoE devices per converter
• Ability to be powered by either AC or DC power source
• Industrial hardened temperature ranges for outdoor applications
• Determines and delivers the specific power level required by the PD
• Fully configurable DIP-switches for easy set up:
– Link Fault Propagation Modes
– PoE Power Reset on fiber Rx loss that automatically resets



Leverage the Benefits of Fiber
There are several solutions available to extend the distances of PoE network links, including LAN extenders that convert Ethernet to DSL, UTP to coax converters and wireless technology. When you’re going long distance, however, fiber optic cabling provides several advantages over these technologies.

Unlike copper, fiber extends network distances up to 87 miles (140 kilometers) per link with no data deterioration over distance (signal deterioration is to be expected in copper cabling). LAN extenders can only extend network distances about 3,300 feet, but a data rate of 100 Mbps can drop by 70 percent at longer distances.

Fiber cabling provides security benefits as well. It is a secure medium that generates no electro-magnetic emission and is very difficult to tap. Fiber is also very reliable because it is not susceptible to electrical interference, or data loss due to temperature or atmospheric conditions.

Installation Steps
1) Please turn off the signal source and the device's power, installation with power on may damage the device;
2) Check if the network cable and other transmission line that will be used is occupied by other device;
3) Use a network cable to connect video to POE Ethernet Optical Transceiver's LAN port with PoE IP camera or other PoE network device;
4) Use two single mode double optical fibers to connect two converter's optical port, please attention the optical fiber which connect the RX and TX port should be across; that means one optical fiber, one side is to connect the optical module TX port, the other side should connect the RX port;
5) Check if the installation is correct and device is good, make sure all the connection is reliable and power up the system;
6) Make sure the Ethernet and PoE power supply is working normal.
Another Application:

Wednesday, June 17, 2015

Selecting a PoE Switch

You just picked up some new Power over Ethernet devices – a few of the hottest new IP cameras. However, after opening the box you run into a series of unexpected problems. No its a really powerful decision.
First: Each camera comes equipped with its PoE injector capable of supplying the appropriate level of power.  However, prior to even mocking up your panel it becomes clear – four PoE injectors and a standard Ethernet switch will not fit.
In an effort to maintain a reasonable panel size, you ditch the PoE injectors in favor of a Power over Ethernet switch, a single product that will replace all four injectors and provide Ethernet switching.  So far so good.

Second: After deciding that a PoE switch will best suit your need, you set out on a search for the cheapest PoE switch you can find.  Before long you realize the injectors were provided so that the cameras receive the exact amount of power they are optimized to run at.  With this new concern in mind, the search moves from the “cheapest switch” to the ”right switch.” In order to identify the right switch, you will need some information… but where do you look?

You are able to find a small label printed on the bottom near the Ethernet port of the camera – something that specifies how this camera can be powered. Now you have some numbers to shoot for, but what exactly do they mean?
While listed on the label in the above order, Power over Ethernet is best addressed in this order:-

1.     Is this a Power over Ethernet device?
A.     Will the device accept Power and data through the Ethernet port? Has the device been designed to make use of Power over Ethernet.

2.     Is this device IEEE 802.3af or IEEE 802.3at compliant?
A.     How much power will the device draw? Both IEEE 802.3af and 802.3at are based off +48VDC voltage but differ in wattage.
B.     IEEE 802.3af = “Standard PoE” = devices consuming up to 12.95W of PoE power IEEE 802.3at = “PoE Plus, High-Power PoE” = devices consuming up to 25.50W of PoE power

3.     Which class of Powered Devices (PD) is the device a member of?
A.     PoE capability and power level compliance – the class level of Powered Devices further specifies how much power the device will draw
Class 1 = 0.44 – 3.84W “Very low power”
Class 2 = 3.84 – 6.49W “Low power” 
Class 3 = 6.49 – 12.95W “Mid power” 
Class 4 = 12.95 – 25.5W “High power, suitable only for IEEE 802.3at PoE”


Translating the above power label again we find:
1.     Is this a Power over Ethernet device? Yes, this camera can accept PoE
2.     Is this device IEEE 802.3af or IEEE 802.3at compliant? IEEE 802.3af – the maximum it will draw is 12.95W at 48VDC
3.     Which class of Powered Devices (PD) is the device a member of? Class 2 – this device will draw between 3.84 and 6.49W – it is a “low power” device

After finding a Power over Ethernet switch that will provide suitable power conditions on a per-port basis, there is one final element to consider – power budget.
Will the switch you choose provide enough power per port for each camera? You bought four cameras to use four cameras, not to use just one or two.  Your choice in a Power over Ethernet switch needs to reflect this… Will the switch provide suitable power to all ports at all times?
Finally, after considering space in your panel, power demands of one camera, power ability of a switch for one port, and powering ability of a switch across all ports, you are prepared to make a decision!



Tuesday, June 16, 2015

Simple Ways to Clean your Camera Lens

Three Simple Ways to Clean your Camera Lens

Dust, rain, and bugs can have a great impact on the quality of your camera’s picture, but with the following easy tips, you can keep the image quality looking great throughout the life of your security camera.
1. Distilled Water – Put some distilled water into a squeeze bottle with small tip. You’ll want to gently apply some water droplets, and then blot gently with lens tissue or another clean, lint-free, scratch-free material.
2. Baby Shampoo – A mild surfactant like Johnson’s baby shampoo (diluted with water) lightly applied to the glass and blotted dry is a great way to remove dust, spider webs, and oil compounds from areas that create steam from oil based foods.
3. Hot Air – By using a hair dryer to a dry lens you are heating up the glass to a point where the molecules are now looser and easier to remove.  The reason why waxing a car is such a chore is the effort needed to create heat by rubbing the surface to warm up the compounds so they can be removed.  A simple hair dryer to a lint free cloth can do the trick for minor cleaning needs.

Saturday, June 6, 2015

Megapixels Resolution in PPI

Megapixels Resolution in PPI

Now a days IP Camera markets going to use 7MP, 10MP, 16MP resolution for Better background information (photo quality).
The first things to understand is that in digital imaging, the only thing that really counts about a file is how many pixels are in a file. Terms like megapixels, DPI and file sizes in megabytes only confuse the issue. In the end, all digital images are simply X pixels by Y pixels big (by Z bits of colour data but we can ignore that for now)

Pixels Per Inch is the key term. It is a description of the logical number of pixels from your original image (X pixels by Y pixels, remember) that will be used to tell the printer to print one inch on paper. Assuming a sharp original shot with good technique (see resolution discussion below), the higher the PPI, the better the quality print you can achieve - this is testably true even well beyond most claims of 360 PPI being the most you need ... 600 PPI images can easily be seen to be much sharper again if this data is available at good quality from the original file).

Here's why:
1. A megapixel is 1 million pixels. It's an area measurement like square feet.
2. A typical 8 megapixel camera produces images that are 3266 x 2450* pixels.
If you multiply 3266 by 2450, you get 8,001,700 or 8 million pixels.
3.  To find the largest photo quality image you can print, simply divide each dimension by 300:
3266 / 300 = 10.89 inches
2450 / 300 = 8.17 inches

4.  If you are not publishing your images in a book or magazine, and you're just making prints for yourself or your friends, you can "cheat". Good quality inkjet printers can make a nice looking print at 250 or 200ppi. At 200ppi, the maximum print size becomes:
3266 / 200 = 16.33 inches
2450 / 200 = 12.25 inches

Megapixels vs. Maximum Print Size Chart

Megapixels
Pixel Resolution*
Print Size @ 300ppi
Print size @ 200ppi
Print size @ 150ppi**
3
2048 x 1536
6.82" x 5.12"
10.24" x 7.68"
13.65" x 10.24"
4
2464 x 1632
8.21" x 5.44"
12.32" x 8.16"
16.42" x 10.88"
6
3008 x 2000
10.02" x 6.67"
15.04" x 10.00"
20.05" x 13.34"
8
3264 x 2448
10.88" x 8.16"
16.32" x 12.24"
21.76" x 16.32"
10
3872 x 2592
12.91" x 8.64"
19.36" x 12.96"
25.81" x 17.28"
12
4290 x 2800
14.30" x 9.34"
21.45" x 14.00"
28.60" x 18.67"
16
4920 x 3264
16.40" x 10.88"
24.60" x 16.32"
32.80" x 21.76"
36, Nikon D800
7360 x 4912
24.53" x 16.37"
36.80" x 24.56"
49.06" x 32.74"


*Typical Resolution. Actual pixel dimensions vary from camera to camera.
**At 150ppi, printed images will have visible pixels and details will look "fuzzy".