Digital ptz control. The use of PTZ cameras in video surveillance systems. Utility for testing cameras with Pelco-D protocol

The Line video surveillance system controls PTZ cameras using an RS-485 interface converter. IP PTZ cameras are controlled by the system via Ethernet interface. Combined use of PTZ and overview cameras is possible, which allows you to automate the transition of a PTZ camera to the zone of motion detected. This function of the program is useful for protected objects with a large territory.
You can restrict access to PTZ control to any user. Just uncheck the box in its settings.

Supports major control protocols (PTZ):

Pelco D / Pelco P;
Lilin v. 1 / Lilin v. 2;
Samsung SCC-C;
Panasonic;

Panasonic New;
TOA;
ZC-NAF27.

Standard

By launching the widget, you can fine-tune the position of the camera and go to the preset. All possible presets have a preview mode.

Visualization of memorized PTZ camera presets has been implemented, allowing you to see the location of the camera before starting to navigate to the selected preset. When saving a preset, the program automatically remembers a snapshot of the camera screen, which allows the user to visually determine the desired transition.

Advanced

When you hover the cursor over the center of the picture, a joystick appears. By holding down the mouse button, you can turn the camera in the direction of the joystick movement. The further the joystick is from the center, the faster the camera turns.

Click on the image to view

Control methods

PTZ cameras can be controlled using a mouse, joystick or USB remote control. There are also keyboard shortcuts.

The CNB-M1360PL PTZ (controlled) camera fell into the hands of a short time. This type of cameras is controlled via the Rs-485 interface, usually using the Pelco-D protocol. From the control capabilities, the protocol supports: horizontal rotation, vertical tilt, zoom, focus, iris, OSD (On Screen Display) control, various settings and various other features. But not always all of the above may be present on the selected camera, the camera that has fallen into the hands of the available ones: zoom, focus and on / off.

In the article I will share my experience of communicating with this camera, a description of the Pelco D protocol, a program for testing such video cameras and an example of implementing a camera control code over Rs-485 using the Pelco D protocol.

Larger camera view.

This, one might say, modular, without a box-type video camera, it is one of the cheapest and most affordable, the average price is around 6000r (at the time of writing the article 11/04/2017). True, it is without a turntable included, which is a little sad for the first acquaintance with such cameras... The camera is equipped with 12x optical zoom and up to 120 digital, auto focus, day / night mode switching and other functionality standard for custom video cameras. From the controls on this camera are available: zoom, focus and on / off.

It can be equipped with a camera OSD menu control board, which also contains a BNC connector for video output, connectors for power and Rs-485 lines, and a UART-Rs485 interface converter. In this case, only the Tx line with a logic level of 5V goes to the camera.

In the photo of the control board, top view, 1 pin is signed on the connector.

The OSD menu is controlled by 5 buttons using the ad-key interface, which I have already considered using the example of a simple modular video camera -. The connection diagram of the buttons is slightly different from the one drawn earlier, but the meaning is the same.

The buttons in this camera are responsible not only for navigating the on-screen menu, but also for controlling the zoom and focus.

In the OSD, in addition to the image settings, you can select one of the two control protocols Pelco D or DXP and set the camera number for addressing it on the Rs-485 line. Several cameras with the same numbers can be put on one line in order to control them simultaneously or with different numbers for separate control. Interface settings: 2400 baud rate and standard 8N1. Other cameras may have different speeds, but they are in the standard range of 2400 to 115200.

Pelco D

Pelco Protocol Brief D.
Sends of 7 bytes are sent to the cameras from the remote control:

Checksum - 1 byte is equal to the sum of 5 bytes: from 2 to 6.

The Pelco D protocol can send 15 standard commands to control cameras, it can be used to remotely configure cameras (but not all cameras support this or their manufacturers use non-standard / their own commands and carefully hide them) and control the on-screen OSD menu (also not all cameras support). Because Since the copy on hand only supports a limited set of standard commands, I will not consider additional options for remote camera settings.

Standard commands:

	bit 7	bit 6	bit 5	bit 4	bit 3	bit 2	bit 1	bit 0
Team 1	Sense	eserved	Reserved	Auto / Manual Scan	Camera on / off	Iris Close	Iris open	Focus Near
Team 2	Focus far	Zoom wide	Zoom tele	Tilt down	Tilt up	Pan Left	Pan right	Always 0

The Sense bit is used in conjunction with the Auto / Manual Scan and Camera on / off bits.

Note that after turning on the commands for movement along the axes or focus and zoom, the camera will move until it reaches the extreme position. You can stop the movement with the "stop" command.

On the Internet you can find detailed description Pelco-D protocol in English.

When working with the camera, I connected it to a computer via a $ 2 USB-Rs485 converter (in the first photo in the lower right corner), built on the basis of a USB-UART ch340 interface converter and a UART-Rs485 MAX485 converter. This, the cheapest converter, has no galvanic isolation and only 2 outputs Rs485 A + and A-, there is no common wire! When connecting equipment via 485 lines, it is advisable to use galvanic isolation and also connect the converters with a common wire, because if the power circuits of the devices are not combined by them over long distances, the devices may work incorrectly, malfunction or burn out. What happened to me, but with a wire length of ~ 60cm. The converter was connected to the computer, and the camera was powered from a laboratory power supply, but the power supply did not have a ground wire (I forgot that the used power supply unit has no grounding on the mains plug, all other laboratory equipment and a computer at the workplace have), which when turning it on and off caused the MAX485 chip in the Chinese converter to burn out. Be careful and, better, do not skimp on converters and wires.

Utility for testing cameras with Pelco-D protocol

To work with the camera, or rather to check its functionality, I wrote a simple utility.

When connecting the interface converter to a computer in the computer, a new virtual port appears (depending on the converter). You can connect to it in the program, having previously set the port speed required for the cameras used. The program provides the ability to control the camera through command bits, prescribe the parcel manually and the minimum standard functionality for rotating the camera, controlling its zoom, focus and aperture.

The program uses standard settings for COM port 8N1 (8 bits, no parity, 1 stop bit). The utility does not control the COM port control lines (RTS and DTR).

Sample code

An example implementation of the code for controlling a PTZ camera using the Pelco D protocol will look like this:

Unsigned char ptz_camera_adress; // camera address // sending data over the Rs-485 line // input: * data - a pointer to the array of sent data void ptz_camera_send_data (char * data) (rs485_mode_send_data (); while (* data) (send_uart (* data); + + data;) rs485_mode_received_data ();) // sending a send to PTZ cameras // input: adress - camera address, cmd1 and cmd2 - commands 1 and 2, data1 and data2 - data 1 and 2 void ptz_camera_data_send (unsigned char adress, unsigned char cmd1, unsigned char cmd2, unsigned char data1, unsigned char data2) (char ptz_camera_txBuff; ptz_camera_txBuff = 0xFF; ptz_camera_txBuff = ptz_camera_adress; ptz_camera_txBuff = cmd1; ptz_camera_txBuff = cmd2; ptz_camera_txBuff = data1; ptz_camera_txBuff = data2; ptz_camera_txBuff = ptz_camera_adress + cmd1 + cmd2 + data1 + data2; ptz_camera_send_data (ptz_camera_txBuff);) // camera on void ptz_camera_on (void) (ptz_camera_data_send (ptz_camera_adress, 0x88,0x00,0x00,0x00,0x00x00);) // camera off 0x00,0x0 0.0x00); )

rs485_mode_send_data ()- switching the Rs-485 module to data transmission
send_uart (char data)- function of sending data via UART
rs485_mode_received_data ()- switching the Rs-485 module to receive data

In some areas modern life PTZ cameras have gained popularity. From the decoding of the abbreviation PTZ, we can conclude that such cameras provide the ability to control the moving mechanism (Pan / Tilt / Zoom - pan / tilt / zoom). Thus, you can control PTZ cameras remotely, manually adjust its position with the ability to rotate 360 °, being behind the monitor screen, and, if necessary, enlarge the image. This feature of this type of device allows you to replace several static cameras with one PTZ. You can also program the device to automatically respond to changing events in the frame.

PTZ camera control

The ability to control PTZ cameras is realized due to the presence of an electromechanical drive in the devices, which provides the ability to rotate and tilt the PTZ camera. Also, these cameras are equipped with a built-in optical zoom, which allows you to remotely adjust the focal length of the lens. The mechanism is controlled remotely using the connection digital cameras via a network protocol, or by means of a control panel for analog cameras.

IN manual control There is nothing fancy with cameras - the operator sits at the computer screen, and using a joystick or keyboard, he rotates the camera in the required direction.

Automation of modern PTZ cameras works on the principle of reaction to changes in pixels in a certain area of the frame. In other words, the device program, when movement occurs in the frame area, notices this, and when the object moves in space, it turns the camera after it, and stops the camera when the movement stops. After the moving object has left the field of view, the camera automatically returns to its original position. It is also possible to set up sensitive areas of the frame, in the event of movement in which the automatic will be triggered. It is possible to make insensitive those zones in which movement occurs constantly, and, in principle, is not a significant reason for the sensor to be triggered, for example, an enclosure with a dog.

Most PTZ cameras have an automatic patrol function, which allows the camera to automatically move along a given route. Depending on the model, you can set from 8 to 200 presets.

The auto-flip function provides automatic rotation of the camera unit 360 ° when the mechanical stop is reached, after which the camera continues to move along the specified route.

Other characteristics

Optical zoom lens analog PTZ cameras can reach 36x, digital - 22x. The maximum digital zoom is 18x.

As well as fixed cameras, PTZ devices can be equipped with various event sensors with reaction to motion, noise, etc. The standard function of automatic switching to black-and-white shooting mode after dark (day / night function) is also implemented. Among other things, all dome and hemispherical devices are equipped with built-in IR illumination diodes for.

Execution options

PTZ cameras, like static ones, differ in their body design. In addition to the subdivision into outdoor and indoor, PTZ cameras are box, dome and hemispherical, but dome video capture devices are the most popular due to their reliability due to the location of the entire mechanism under the "dome". The vandal-proof housing of PTZ dome cameras reliably protects them from all kinds of mechanical influences and adverse operating conditions.

With the dome camera, you can adjust the field of view at right angles downward and pan 360 °. Due to the structural features of spherical dome cameras, they all have powerful IR illumination.

Hemispherical outdoor cameras, like dome ones, have high protection against environmental influences due to the location of all parts of the movable mechanism inside a sealed hemisphere.

The mechanism of box-type PTZ cameras closely borders on environment, therefore, their resistance to weathering is very low. Because of this feature, the use of box-type PTZ cameras is limited to internal rooms in the absence of unfavorable conditions in the form of high humidity and dust.

Varieties of PTZ cameras

Like any other camera, PTZ has a clear distinction between analog and digital devices.

Today it is most expedient to use as analog PTZ cameras. The choice in favor of this type of device can be made based on the indicators of ease of connection, as well as high image resolution (HD, Full HD), comparable to IP video surveillance devices, which old analog cameras cannot boast of. Easy to connect AHD cameras due to the possibility of transmitting video, audio, and control of the rotary mechanism over one coaxial, when, as for simple analog devices, it would be necessary to lay a separate cable for control.

PTZ IP cameras have a high resolution images, and can also be directly connected to the Internet or integrated with cloud services for remote video surveillance and control of the driving mechanism of the camera from any gadget from anywhere in the world if there is an Internet connection. All signals are transmitted over one UTP cable () type 5e.

Dome PTZ IP WiFi Camera IVUE-IV8513PZ

As an example of an outdoor PTZ IP camera, let's take the IVUE IV8513PZ model, with a 1.3 MP matrix, and a maximum recording resolution of 720p (1280x720). The implementation of Wi-Fi technology provides the ability to wirelessly connect the camera to a router for setting up remote access via the Internet, accessing the device from a mobile phone or computer. It also implements WDR (wide dynamic range) technology, which allows video surveillance in difficult conditions with uneven lighting distribution. Viewing the video stream from the camera and controlling the rotary mechanism is carried out through a CMS program or a browser interface. IVUE IV8513PZ has a built-in motion sensor, IR cut filter and IR illumination with a range of up to 10 meters. Operating temperature range from -30 to + 50 ° C. The cost of the device at the time of this writing is about 21 tr. By the way, the price range of almost all PTZ cameras is approximately equal to or starts from this figure, with the exception of some models.

Scope and application features

Thanks to swivel mechanism it is possible with one PTZ camera to provide control over the entire territory. To date given type cameras are widely used in store security systems, large shopping centers, banks, schools, in general, wherever you need a circular view of the territory of the object and the possibility of an instant increase in the focus of an alarming event.

Most often to maximize the effectiveness of a video surveillance system rotary PTZ Cameras are used in conjunction with fixed video capture devices, when static cameras are constantly "vigil", and rotary ones are included in the work in case of need for a quick reaction to an extraordinary event in order to obtain decent image detail by optical zoom.

Based on the installation site, PTZ cameras can be used both indoors and outdoors. are equipped with a special sealed casing that protects the device from low and high temperatures, precipitation, moisture and dust. A heating system is built into the body of some outdoor cameras, which ensures uninterrupted operation of the device even in severe frosts. Therefore, when choosing cameras for operation in low temperatures, it is necessary to pay attention to the operating temperature range. This parameter for most types of outdoor PTZ cameras is in the range from -50 to + 60 ° C.

Read with this:

Did you like the article? Share with your friends on social networks!

Until recently, video surveillance systems used mainly cameras with a fixed angle, field of view, and focal length. The disadvantage of this method is the need to use a large number of CCTV cameras, the presence of dead zones and the impossibility of obtaining a clear picture of the intruder at different distances from the camera.

The solution to these problems was the development of devices that allow remote control key functions CCTV Cameras.

The scope of PTZ cameras is rather narrow due to their high cost. Their use is most effective at facilities of a large area with a complex configuration, which have several controlled areas. In this case, the use of one PTZ video camera can replace several conventional - fixed ones and will be financially justified.

In the case of integrating video surveillance into a security system, such cameras can be used to check the alarm and localize the intruder. Modern systems analytical management make it possible to use PTZ cameras for active monitoring of the intruder - they lead the object in the area of responsibility.

MAIN TYPES OF EXECUTIVE DEVICES

PTZ - (Pan Tilt Zoom).

An electro-mechanical device that performs the functions of tilting, rotating and changing focal length... Currently, there are two types of PTZ devices:

A separate product to which the casing is attached to accommodate a box-type CCTV camera.
Drive as part of a mechanism integrated into the dome camera.

Varifocal zoom lenses.

Lenses with a movable lens system that interconnectedly move relative to each other so that when the distance to the object or scale changes dynamically, the picture is always in focus. External control can be carried out over a powered zoom. Remote change of the focal length will allow the person on duty to quickly bring the object closer to examine individual details.

The most effective, but also expensive, models are devices that have the ability to preset the position. Camcorders with such lenses achieve the maximum effect in combination with PTZ devices.

PTZ CAMERA CONTROL

INTERNET CONTROL OF CCTV CAMERAS

With the proliferation of digital IP - surveillance cameras that transmit information directly over local network Ethernet / WiFi without laying special communications, the issue of controlling video cameras through various external devices and the Internet has become an urgent issue.

Transmission of video and control commands carried out by cables common use and, moreover, over radio channels it has insufficient security, despite the spread of various encryption algorithms. Therefore, such video surveillance systems are widely used in private homes and small companies. They are often integrated into security and alarm systems.

The most basic (freeware and shareware) programs offer a limited set of functions:

enable / disable recording;
viewing an image in On-Line mode or from an archive;
image search by several parameters;
PTZ module rotation control.

In most cases, a WEB-interface is used for control with varying degrees of automation of searching and configuring cameras on the Internet.

There are two sources software, which is used to remotely control CCTV cameras over the Internet.

The first is software supplied by video surveillance equipment manufacturers. As a rule, such software is only compatible with cameras. own production... The second source is business applications and their free versions, which offer a wide range of functions, including analytical ones, and are compatible with most popular brands.

These programs include:

NetStation from Armo Systems;
CMS from VidStar;
Intellect from the iTV company.

It is enough to install such software on your computer and the operator will have a rather impressive set of functions with the ability to automate many control processes PTZ video cameras si:

patrolling;
choice of target for tracking;
prioritization and detailing;
automatic selection and activation of a PTZ surveillance camera to guide a target through several areas of responsibility.

Also, many software modules have been developed for mobile devices: smartphones, tablets, etc. Their functionality is aimed at viewing images and controlling PTZ cameras in real time. For example, the program "Line 7.0", which is released in various versions for the most popular operating systems: iOS, Android, Windows Phone and Windows Mobile.

CLOUD CAMERA CONTROL

Cloud-based video surveillance services VSaaS are one of the most promising trends in video surveillance and remote camera control. Usually cloud services only offer remote viewing without analytics and management features. But well-known camcorder manufacturers as they are released new products include in the functionality and the ability to remotely control.

Cloud services are offered by companies such as:

Axis and its cloud resource Axis AVHS;

DSSL - Trassir Cloud;

Domestic companies - Satellite Innovation;

Mobile operator - Megafon, etc.

Thus, remote control of various functions and PTZ actuators of video cameras can be realized different ways, both with the involvement of large funds and specialists, and independently with a minimum budget. One thing is certain, remote control will significantly increase the efficiency of the video surveillance system at the facility.

Connecting a PTZ security camera is much like connecting a standard security camera. Most PTZ cameras have three connectors: for power supply, video transmission and data transmission. You will find audio in some PTZ cameras, but this is quite rare.

The first step is to correctly determine the power requirements of the PTZ video camera. Most of these cameras operate on a 24 V or 12 V DC source. You should also check the camera's amperage requirements. Since they have a built-in motor, they consume more current. For example, if a PTZ camera is rated as 12 V DC / 2 A, you must ensure that it draws at least 4 A of current.

After you have connected the power, now you need to connect the wires for the video transmission. Often in controlled video cameras they are used for video transmission. Many CCTV installers use Category 5 (CAT5) cable to connect to PTZ cameras. Use a pair of CAT5 cable for power transmission and a single conductor cable for video signal transmission.

If your PTZ camera has audio support, you can connect a pair of audio cables. In many cases, when installing surveillance cameras, engineers use CAT5 cables to transfer not only video and data, but also audio signal.

The data wires are connected last. Commands are transmitted along them, which, for example, make the camera rotate. RS485 is a very common interface used for data transmission. You can use the joystick or to control the PTZ camera. But you have to check if they are compatible with each other. Most PTZ cameras use the Pelco protocol and must be supported by DVRs and controllers. You must set PTZ ID, baud rate and protocol.

To program PTZ camera you may need to open its case. Inside you will find a jumper block, also known as a DIP switch. It can be used to program PTZ ID, baud rate and protocol. In the DVR settings, go to the main menu, find the PTZ configurations and copy the same values. If you are using a joystick, change the settings using the button combinations.

We wish you the best in connecting your Pan Tilt Zoom camera.

Source cctvdvrsystem.co.uk. Translated bysite administratorElena Ponomarenko