Video intercom calling panel with camera - Types and connection diagrams

Block diagram The most common block diagram of a four-wire video intercom is shown in the figure: Depending on the model of the video intercom, you can connect from one to several calling panels to it (usually no more than three). When you press the call button on the calling panel, a ringing melody plays on the intercom and a video image from the camera installed in the calling panel is played. Pressing the “Open” button on the intercom closes the contacts (the so-called “dry contact”) of the lock control on the calling panel - the electromechanical or magnetic lock is activated and the door opens. To switch between calling panels, the intercom has a button called “Door” or similar. By pressing this button, the calling panels are switched cyclically. In addition, some video intercoms provide for the connection of slave monitors with the ability to organize communication between them - the “Interphone” function. A four-wire line is used to transmit signals between the Call Panel and the Intercom:

1. Power - power supply to the calling panel
2. Audio - transmission of voice and control signals
3. Video - video transmission
4. Ground - common wire, “ground”

According to flashwolf

from the conference “Interfaces and protocols of intercoms” the following voltages are present on the lines:

However, when connecting the calling panel to the Samsung SHT-3005 video intercom, the voltages on the lines are slightly different:

But the general principle remains the same - in the initial state there is a positive voltage on the Audio line, and on the Power line the voltage is close to zero (there is no need to power the calling panel if there is no established connection). When the connection is established, 12V voltage appears on the Power line, which is necessary to power the conversation unit and video camera in the calling panel. Now let's try to figure out how the ringing signal and the door opening signal are generated. To do this, you need to understand what the calling panel is and how it works. Call panel

One of the most popular calling panels is the anti-vandal video panel AVC-305: Using its example, we will consider the algorithm of operation of the calling panel together with a video intercom. On the Internet you can find many sites with a circuit diagram for this video panel, but, unfortunately, all of these sites present the same version of this circuit with the same significant error - the zener diode in the door opening signal recognition circuit is switched in the forward direction. In this connection, the zener diode will work like a regular diode and the lock opening contacts will always be closed. The corrected version of the diagram is shown below:

Please note that it is possible that the circuit also contains errors in the conversational part, but they do not affect the interaction with the intercom, so the analysis of the conversational part was not carried out. So, what do we see in the above diagram? The first thing you can find out is that the ringing signal is generated by shorting the Audio line to the common wire through a 100 Ohm resistance. There is no contact bounce compensation circuit for the “Call” button, therefore compensation must be carried out in the video intercom itself. The next important node for us is the node for generating the door opening signal. This unit is made of transistor VT1, resistors R4, R5, capacitor C2, zener diode VD9 and relay K1, together with a protective diode VD8. Resistor R5 together with the zener diode VD9 form a threshold device, the response voltage of which corresponds to the stabilization voltage of the zener diode. In our case it is 10V. Resistor R4 limits the base current of transistor VT1 operating in switching mode. Capacitor C2 is designed to filter impulse noise. It should also be noted that the Video line is connected to the ground bus through a 1 kOhm resistor R24.

Simulation of the door opening signal generation circuit

Let's simulate the circuit for generating a door opening signal.

The project archive for ISIS can be found here. By changing the voltage with resistor RV2, we achieve “ignition” of LED D2. From the simulation it is clear that, as intended, the LED “lights up” when the input voltage is more than 10.6 V, because at a voltage of 10V, a breakdown of the zener diode occurs and a voltage appears at its output, which, passing through resistor R2 to the base of the transistor, causes the base current to flow and the transistor opens. Those interested can experiment and change the polarity of the zener diode to the one indicated on the diagrams of the calling panel on the Internet - the transistor will be open when the input voltage is more than 1 V.

Features of the Samsung SHT-3005 video intercom

As already noted, the Samsung SHT-3005 video intercom differs slightly in the voltage levels on the communication lines. In addition, it has another significant difference - it does not send a lock opening signal to the Audio line. To open the lock, it has a separate connector, which contains “dry” contacts for opening the lock. Moreover, it is possible to organize control of two locks. Thus, when connecting the AVC-305 calling panel to this video intercom, it will not be possible to organize the transmission of the lock opening signal without modifying the intercom, or it will be necessary to lay two more wires specifically for opening the lock.

Sing half a song - half the job

So what do we have now? The algorithms and four-wire intercoms are sorted out, the approximate parameters of the signals are determined. Half of the work in pairing intercoms is done. Now the most creative (and most interesting) part remains - the development of the interface circuit, its implementation in hardware, field testing, correction of the operating algorithm, and finally, the ceremonial completion of the project!

A video intercom is no longer some kind of ultra-fashionable, luxurious and expensive household equipment. Nowadays, such devices can be seen not only on elite cottages, but also on the entrance doors of standard high-rise buildings.

Read also: What is a band saw for wood?

A rationally selected calling panel with a camera for a video intercom will have a long service life and ensure accurate identification of guests, which guarantees a high level of security for building residents. Let's consider the main types and installation diagrams for connecting such devices.

Components of video intercom devices

A video intercom is a rather complex device. The number of its structural elements in various modifications depends on the set of options and the availability of the ability to connect certain additional modules that expand the main functionality.

Any intercom consists of the following basic elements:

Video intercom display or control panel , to which the video signal is transmitted from a video camera installed in the calling panel or from additional independent cameras. The intercom control panel is installed indoors.

Its functionality is:

1. Control of electromechanical or electromagnetic locks;
2. Audio and video communication with the guest;
3. Recording video stream from CCTV cameras;
4. Call forwarding to another control panel, if any;

Access locking device , consisting of an electromagnetic or electromechanical lock. Such locks are opened either remotely from a button on the video intercom control panel or using a special card reader and intercom keys. If there is a loss of electricity at the facility, and the intercom system does not have an uninterruptible battery, then the electromechanical lock is blocked; it can be opened mechanically from the outside using the regular key included in the kit.

Below I have presented the standard delivery kit for an electromechanical and electromagnetic lock.

Call panel , which can have an extensive range of functions. In the minimum configuration, it is equipped with a signal key and address dialing buttons; in more complex configurations, it is equipped with fingerprint, voice or retina recognition modules. As an example of a standard modification of a calling panel for outdoor use with a basic set of options, we can mention Optimus brand products.

The photo shows the delivery kit for the calling panel with the Optimus DS-700 camera

Power unit . One or more 12 V power supplies that provide power to the various functional modules of the system. Power supplies are simple and uninterruptible. The latter, after turning off the light, continue to work due to the battery installed in it.

In general, the access control system can be modified within very wide limits. For example, in certain modifications it is possible to install an additional calling panel (black and white or color), additional displays, video cameras and microphones. Moreover, each of the above blocks can also have a different set of options.

Intercom brands and number of subscribers

Maloabonensky - installed on sites and in private country houses. These devices can serve only one subscriber, for example, in cottages, at security posts, at the entrance to a house or at the entrance to a site. Multi-subscriber – designed for entrances to multi-storey and apartment buildings, administrative buildings.

Not so long ago, these structures could only serve 6 people, but progress does not stand still, and at the moment you can buy intercoms of various configurations that can serve more than 1000 subscribers, while making dozens of entrances accessible.

Different brands of intercoms
The installation of an entrance intercom should be carried out by specialists from the company that will subsequently service it. Device types:

1. Coordinate matrix - connecting a video intercom to an entrance intercom depends on the blocks that subscribers install, for example, if there are 30 blocks, then the same number of wires will have to be pulled. The coordinated entrance intercom is characterized by an affordable price, but with such a large number of wires, it may not work correctly, since the network is often overloaded.
2. Digital intercoms are not cheap, but they are connected using two wires. But it is worth noting that neighbors can listen to conversations and devices often fail. In addition, they may send a false call or not open the entrance door with an intercom.

   
   Digital intercom connection diagram

   Read also:  Which automatic circuit breaker (RCD) should be installed on a washing machine: expert advice
3. Wireless systems - can be connected without the use of new communications, but through telephone lines. They also connect using IP. These are elite series intercoms, and they can work via Wi-Fi connections or via the Internet. This system can have a call panel with buttons, a camera, internal equipment - a handset for an entrance intercom or a small screen. These structures are controlled from a tablet or smartphone, but you can also use a simple handset that is installed next to the entrance door to the apartment. But if the owner decides to connect the handset, he will be deprived of the opportunity to use video communication. If video surveillance is necessary, it is better to order a comprehensive installation.

Types of intercom calling panels

It is important to understand that different access control systems have varying degrees of compatibility of their constituent elements.

Most manufacturers, in order to create strictly defined functionality at minimal cost and ensure maximum reliability of video intercom systems, recommend using only components of their own brand.

However, no one forbids creating a prefabricated system, for example, taking a calling panel from one brand, and a control module or video camera from another. The question of the feasibility of such a solution lies in cost, compatibility and desired parameters, such as:

• — protection from moisture;
• — operating range of temperature fluctuations;
• — class of protection against vandalism;
• — functionality (call button, presence of a keyboard, intercoms and other auxiliary elements);
• — type of video camera and its parameters (color, black and white, viewing angle, resolution, photosensitivity);
• — compatibility with keys of a particular class;
• - additional options.

In addition to the above parameters, video intercom calling panels can be selected by the future owner based on compatibility with magnetic or electronic keys already used on doors.

Video intercom systems on the market are conventionally divided into two groups:

Street

An outdoor intercom calling panel is a device designed for use in harsh weather conditions, has a high degree of protection against vandalism and mechanical damage, and does not require scheduled maintenance. This is why most components of outdoor panels are made of metal.

For example, a standard outdoor calling panel can withstand temperatures down to -10°C. Some manufacturers also create ultra-frost-resistant models that can function even at -40°C.

Vandal-proof modifications of the video intercom use designs that can resist almost any malicious mechanical influence. The speakers are reliably protected by a metal mesh, the microphone is hidden in a special way, and the video camera lenses are made of high-strength shockproof glass.

Domestic

The internal part of the video intercom can provide the owner with a wide choice of options - their number depends on the wishes of the user and his financial capabilities. The limit of perfection of such devices is limited only by the level of the latest achievements of scientific and technological progress.

Internal video intercom calling panel

Modifications of video intercoms designed to operate in average conditions (temperature above 0°C, average humidity, absence of vandalism) usually have the following options:

• — fingerprint recognizer;
• — programmable touch keyboard, reminiscent of a smartphone display;
• - motion sensors;
• — external and internal screens for mutual video and audio communication;
• - Possibility of using different types of keys.

As a rule, the video signal on internal panels is much better than on external ones. If there is no need to create anti-vandal protection, external cameras can be selected with maximum light sensitivity and resolution.

By properly placing external video cameras, you can create an effective internal surveillance point for the surrounding area.

Types of intercoms

Intercoms are classified by the number of service subscribers, by the principle of signal transmission, by the type of panel and monitor, and by other mechanical characteristics.

By number of subscribers

The classification is simple.

• Individual - there is only one subscriber device and is located in the hall or hallway. This option is installed in country houses.
• Multi-subscriber – for multi-apartment residential buildings and industrial buildings. From 2 to 1000 users are connected to the output device.

The most popular models are designed for 2–10 users. They serve the landing, entrance, and small office.

By type of transmitted signal

There are audio and video intercoms.

• Audio devices – provides two-way voice communication with the visitor. The models are in demand due to their low cost. However, they do not provide complete security. The caller's face is not visible, so the “guest” can introduce himself as anyone. However, for multi-apartment buildings this option is optimal.
• Video models - the external intercom unit has a built-in camera. The device transmits not only the voice, but also the image of the visitor. This way the subscriber can see the visitor and decide whether to let him through.

Video models are equipped with many additional functions, since their design allows you to improve the device without large additional costs. As a rule, the intercom has a recording device , which allows you to monitor visitors not only online, but also by recording. The system is supplemented with motion sensors , infrared filters to be able to conduct surveillance in the dark, the ability to transmit a signal to the owner of an apartment or house about an intrusion or visit to the phone, and so on.

Video intercoms offer
2 methods of signal transmission .

• Coordinate - each intercom handset is connected to the calling panel with a pair of wires. This is a rather expensive method, so it is used for a small number of subscribers – up to 20 people.
• Digital - the calling panel is connected to a multi-core cable, and users are identified using codes. This option allows you to serve a much larger number of subscribers, as well as connect a new user at any time.

There are also wireless video intercoms . In this case, an Internet connection or Wi-Fi is used to create an indoor and outdoor module. The system is very easy to install and configure, and is rich in functionality. However, if the Internet connection is unstable, its benefits disappear. In addition, the wireless intercom is highly dependent on the distance between the modules and is also sensitive to weather conditions.

By panel type

The calling panel is the main device of the intercom. Usually it is mounted from the outside . But there are models for internal use - on the territory of an enterprise, for example. They are distinguished by purpose.

The external device must meet a number of requirements :

• sealed housing that does not allow dust, dirt, moisture, smog, smoke, etc. to pass through;
• resistance to sudden changes in temperature and humidity;
• resistance to mechanical damage;
• resistance to corrosion - therefore, the body is usually made of durable plastic or a protected metal alloy.

There are also special anti-vandal panels . Such intercoms are embedded in the wall, have mechanical control, and are embedded in metal. The camera is protected by a thick layer of impact-resistant glass.

Internal intercoms are less resistant to all of the above factors, but are cheaper.

The functionality is the same: if necessary, the devices are equipped with conventional or infrared illumination, sensors, and indication.

Additional functions and design elements

In principle, all other auxiliary components not mentioned earlier must expand the functionality of the system and increase its reliability, otherwise they simply do not make sense.

— a canopy covering the outdoor calling panel protects it from moisture in the event of snow or rain;

— an additional call button allows you to invite the concierge if you have lost your own key or, as a guest, have forgotten the specific address of the person you are visiting;

— illumination, which allows you to transmit to the cameras the highest quality image of the visitor at night or in adverse weather conditions.

In addition, video intercom control panels can have an interface for connecting additional cameras in order to organize video surveillance from several points, and also interact with a motion sensor that activates video recording when any monitoring events begin.

Read also: Welding wire purpose requirements chemical composition marking

In order not to waste money on advanced functionality that is unlikely to be useful to you in reality, before purchasing a specific video intercom system, clearly define the tasks that it must perform and take into account the existing operating conditions.

Is it worth saving on professional installation?

The services of installers are not cheap, but the contractor is better equipped with tools and has experience in installing such equipment. If you wish, having basic skills in working with electrical equipment, it is not difficult to install an intercom yourself. But in the event of an unfavorable combination of circumstances or critical errors, the cost of the issue will be a complete replacement of the damaged equipment. Therefore, if you do not have confidence in your own abilities, then it is better to trust the professionals.

Note. Installation specialists not only know exactly how the intercom works and works, but also have proven methods for installing the system in an apartment building. They guarantee precise operation of the lock and no malfunctions. Carrying out the work independently imposes obligations on the installer for the outcome of the operation.

Approximate cost of installation work

The cost of services depends on the volume (one apartment, the entire entrance), complexity (audio intercom, video device), and type of equipment. On average, prices start from 1.5 thousand rubles. This is the installation of an overhead calling panel. A mortise one will cost 3 times more.

Switching an intercom into a multitasking remote access network will cost 3.5 thousand. A calling unit for an apartment building will cost up to 10 thousand rubles. When the estimate is distributed among several residents, the cost of the work will be cheaper than for a single customer.

Call panel connection diagram and tips for making the best choice

The installation of a video intercom system should be carried out in maximum accordance with the recommendations of its manufacturer. This list includes:

• — installation option (placement inside the door leaf, on the wall adjacent to the door, on the surface of the door, etc.);
• — diagram of interaction with other structural elements (lock control unit, door open button, other additional equipment);
• — method of power supply to system components (connection to a standard 220V power line, through its own voltage converter or through a control module for power distribution via internal cables).

In the technical documentation you can find out what types of cables the calling panel is connected to, what types of auxiliary devices it is compatible with, and what maximum operating loads it can withstand.

Connection diagram for a calling panel with a camera with an electromagnetic or electromechanical lock.

How the intercom works and its modules

Types of intercoms are divided depending on the number of users (single and multi-user), as well as by the nature of the work (with audio and video communication). Most often the kit includes:

• intercom handset;
• call module;
• locking device;
• power supply;
• connecting connectors and cables.

Everything is clear with the handset - this is a unit that is required to communicate between the owners of the house and subscribers from outside. The calling module is intended for the opposite purpose. From this panel the code is dialed, as well as the lock is controlled (if a special magnetic key is used). A locking device, operating on the principle of an electromechanical (electronic or electric) lock, is similar to a bolt in a standard door: it is a unit that prevents unauthorized people from accessing an entrance, room, or apartment.

Important. Without a power source and connecting wires, all of the specified parts of the intercom will not function normally or receive electric current. Therefore, this stage of installation is given special importance.

Installation of a video intercom calling panel

To connect we will need:

- multi-core cable for transmitting audio, video, power supply over a distance of up to 40 meters; — a pair of coaxial and two-core cables, allowing you to organize broadcasting over a line up to 500 meters long; - twisted pair cable, line range - up to 50 meters, this type of wire is not recommended for broadcasting color video signals; - a combined cable having a coaxial structure and several simple insulated conductors.

The best option is to choose an outdoor panel that is compatible with existing communication and power lines or has the same number of signal and power lines as the head unit. In addition, you need to consider the type of lock and purchase a call unit that is compatible with it.

Methods for connecting multi-apartment entrance intercoms

By installing an intercom in the entrance, residents can solve many problems through a collective decision. Including restricting access to unwanted guests. Certain qualifications and knowledge of the electrical circuit of the intercom will allow installation even by non-professional installers.

Multi-apartment structures are divided into 2 types:

1. Digital.
2. Coordinate.

Both types are similar in operating principle and completeness, but differ in the methods of switching the internal telephone (handset) in the apartment. The most common brands of equipment are Metakom, Eltis, Cifral, Vizit, Commax, Laskomex.

Digital system

Installation of a digital intercom network, according to the estimate, will cost more than a coordinated one. The point here is not only in a more complex connection diagram, but also in the equipment. And for an apartment building you will need a lot of it, taking into account the extensive switching and floor-to-floor wiring. So think about what is preferable for installing an intercom. And at the same time, coordinate the decision with other residents.

The number of subscribers served is limited: up to 255 people. Wires from individual subscriber handsets are supplied to the main highway, which crosses the entrance vertically. The connection diagram is parallel.

Attention. A serious drawback of the solution is hidden in the interconnection of subscribers with each other, the impossibility of arbitrary disconnection without reconfiguration. Therefore, any force majeure circumstances, including damage to the main line or planned repair work, require re-adjustment of the entire complex of equipment.

Coordinate system

This method is characterized by some external complexity: the tens and ones that form the apartment number are separately connected with a multi-core cable. Some installation difficulties are compensated by the independent, reliable operation of the intercom for each subscriber. The breakdown of individual tubes does not affect the functioning of the entire network.

The only subtlety is to carefully follow the polarity when connecting intra-apartment lines. It is allowed to use terminals (tubes) from several manufacturers; they may not be the same.

Installation of a street panel

How to connect an intercom yourself? The next item is the installation of an outdoor external panel:

1. The approximate height of the element from the ground is 1.6 m.
2. For overhead panels on the door or wall, the locations of the mounting dowels are marked, then holes are drilled according to the marks and the device is attached.
3. For built-in options, lines are drawn for the groove, and the position of the built-in box is noted.
4. Using a chisel, cut the groove, taking into account the thickness of both the built-in element and the corrugated pipe.
5. Install and secure the recessed box with cement.
6. Then place the corrugated tube in the hole. If necessary, secure its position with nails.
7. Carefully putty the fine with the pipe, simultaneously pulling out the nails holding the last one.
8. Now cut the wires from the pipe to the required length and connect them to the street panel.
9. The action ends by fixing the street panel in the built-in box.

Electrical protection and wiring

We continue to talk about how to connect the intercom handset yourself. The connection itself is only possible to an electrical network protected by a 16 A circuit breaker or a 10 A fuse. To ensure the safety of residents, a 30 mA residual current device is also installed.

Two types of power supply are used for the intercom device:

1. The transformer is located separately from the intercom, connected both to it and to the network.
2. The tube is integrated with a transformer and is connected to an outlet using a power cable.

One of the important topics regarding how to connect an entrance intercom yourself is wiring. Make sure that it fits only in corrugated pipes. Therefore, you need to accurately measure the distance from the outer panel to the speaking tube in order to lay the pipes to the required length. The free ends of the wires should protrude approximately 20 cm from them.

Most common models

In our country, equipment for intercom systems is supplied by several large companies. Among them we can highlight such manufacturers as Metakom LLC, the VIZIN group of companies (Visit). Both companies offer comprehensive solutions for organizing remote access control systems (ACS). Both companies present a wide range of intercom equipment.

Based on the proposed elements, you can create low-user and multi-user intercom systems of any configuration. The company's products are distinguished by a high level of quality and engineering. The equipment can operate in difficult weather conditions of our country. Anti-vandal design ensures high durability of products.