Cheapest USAFEQLO USA-A1 PTZ PTZ Camera and Memory Card. What is a PTZ Camera? Digital ptz control

The CNB-M1360PL PTZ (controlled) camera fell into the hands of a short time. This type The cameras are controlled via the Rs-485 interface, usually using the Pelco-D protocol. From the control capabilities, the protocol supports: horizontal rotation, vertical tilt, zoom control, focus, iris, OSD (On Screen Display), 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 zoom, automatic focusing, day / night mode switching and other functions standard for custom camcorders. 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:

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.

You can find a detailed description on the Internet Pelco-D protocol in English.

When working with the camera, I connected it to a computer through a 2-dollar 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 at 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, register 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 of implementation of code for control PTZ cameras oops under 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 an 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

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.

Support for basic control protocols (PTZ):

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.

PTZ cameras are a branch segment of compact video surveillance devices. The developers of this equipment have raised security miniature cameras to a new level by endowing them with more efficient automatic and, in some cases, robotic intelligent control systems. Partially similar technologies were used in the first generations of video surveillance systems, but modern solutions differ noticeably in a number of parameters, which is confirmed by the example of a PTZ camera. What does this mean in practice? First of all, this is a wider opportunity to control the camera settings, moreover, in a remote mode. In addition, the creators of PTZ models pay attention to the basic characteristics of shooting, allowing you to obtain high quality images while maintaining a modest size of the camera itself.

General information about PTZ cameras

This is a non-standard camera, the main difference of which is the presence of a built-in electronic-mechanical drive. Moreover, the matrix itself, which provides fixation of the video stream, is fully consistent with the characteristics of traditional compact cameras for video surveillance. Features are determined by the drive with a robotic control principle, which, by the way, can act as a separate part - a complete set. However, the latest models of this type also differ in their internal structure. Optical zoom, in particular, allows you to change the angle of view that the PTZ camera captures. What is it from the consumer's point of view? In essence, this means a variable with optical reduction and magnification of the target object. Signals to control the drive mechanism and internal sensors can come from the remote control, or they can be generated by controllers that interact with the computer. That is, through software user can customize completely automatic operation cameras.

Main characteristics of the camera

The number of pixels is the main indicator of the quality of work for all types of such cameras. The simplest versions are provided with 0.3 MP matrices, and high-tech ones - with 5 MP modules. The number of recorded frames per second is usually in the range of 6-30 units. Of course, in assessing the image quality, one cannot do without the resolution of the PTZ device - HD cameras, for example, confidently support the 1920x1080 format. At the same time, the aging VGA matrix at 640x480 remains relevant. In security complexes, the use of such modules is often justified. But if the above-described characteristics fully fit into the set of qualities of conventional CCTV cameras, then PTZ has noticeable advantages in the speed of rotation and increase in focus. So, optical zoom can be 36x, and digital 18x. As for the swing speed, in modern models it reaches 400 ° / s. Also, advanced modifications are equipped with 3D positioning technology.

Applications of PTZ equipment

Experts identify two areas in which the operational capabilities of such cameras are most advantageously revealed. These are security systems for security and video communication in conference rooms. In both cases, users value the flexibility of the hardware in terms of control and the virtually unlimited physical installation of the hardware. It is important to note here the systems wireless connection which are supported by a modern PTZ camera. What does this mean during operation? Wireless technologies virtually eliminate the need to run cables to the device. From the point of view of camouflage, this is the optimal solution, since the attacker will have less chances of detecting signs. And vice versa, the operational work of the camera's rotary mechanics will allow tracking what is happening in the room with the most advantageous positioning.

Types of video camera designs

Manufacturers produce cameras of this type in several variations. The most widespread was PTZ camera Hemisphere PTZ. This type is called Speed ​​Dome and is highly resilient. The design itself, due to its geometric shape, minimizes the risk of dust and moisture particles entering the housing.

Another option is a spherical design, which is in many ways similar to hemispherical cameras. These models are usually equipped with powerful infrared illumination and anti-vandal protection. In general, PTZ dome cameras are designed in such a way that all mechanical components of the filling have minimal chance of direct contact with environment... This advantage is especially evident in the cases of street models, which deserve special attention.

Features of street models

Outdoor operation of video surveillance systems requires a number of additional factors to be taken into account. Among them are the nuances of ensuring communication between the camera and the control panel, the organization of the power supply system and the issues of protecting the equipment from external influences. As for protection, the housings usually receive a thermal casing with dust and moisture protection insulation. Some models are additionally equipped with a heater and ventilation system, which provide the ability to cold start at peak negative and positive temperatures. Power can be supplied directly or by batteries. By the way, the use of uninterruptible power supply sources also justifies itself. Even a typical PTZ camera setup can automate the process of switching to backup power in the event of an unstable network power supply. Communication, in turn, is also organized either directly through a cable or wirelessly using a radio module.

Analog and digital models

In analog models, the resulting record is automatically processed by a digital processor. Then the material is sent to an electronic converter, in which the conversion takes place again, but in the opposite mode. The communication connection of such equipment is provided by coaxial wires. The disadvantages of models of this type include low resolution, which does not allow counting on a high-quality image when shooting at long distances. Digital PTZ-cameras of video surveillance also provide for preliminary processing of the signal in the processor, after which the material can be transmitted via the TCP / IP protocol in the originally specified format. The main advantage of digital models is precisely the high-quality "picture", since in terms of communication and mechanical equipment, analog devices in some cases turn out to be a more reliable solution.

Camera control

In addition to setting the basic parameters of shooting, PTZ cameras provide a lot of control possibilities already in the process of direct use of the device. When installing the camera on site, the user can pre-program it with hundreds of preset positions. For each mode, a whole set of position parameters are assumed, including the angle value, zoom level, etc. Some models also allow you to assign individual scripts for automatic scanning. For example, an outdoor PTZ camera is the most developed in this regard, since it has to cover large areas, including those with distant shots. The remote control, in turn, enables tilt correction. For this, a telemetry console is most often used.

PTZ camera manufacturers

High-tech segments are quickly filled with products from large manufacturers. In this case, the situation is somewhat different, since the most successful developments demonstrate less famous companies... The Axis PTZ camera occupies a leading position, modifications of which are focused on both specialized and universal video surveillance tasks. Also noteworthy are suggestions from Dahua, Geovision and complex solutions by Optimus. Samsung engineers have mastered PTZ technology quite well from large world famous brands, although due to the high cost, these products are not so popular in comparison with counterparts from the above-mentioned manufacturers.

Conclusion

The interest of consumers themselves in video surveillance systems of this type is not so expressed. Despite the obvious technological breakthrough of individual solutions, these products still occupy a separate narrow niche. Manufacturers who are keen to develop new options and functionality that a PTZ camera can in principle understand is also aware of this. What does this mean in context overall development segment? At this stage, technologists are betting on optimizing the communication interaction between the camera itself and the control complex. In practice, this will mean a simplified means of organizing communication between individual components of video surveillance systems, and at the same time, a closer convergence of camera mechanics and software.

An alternative to fixed cameras are pan / tilt / zoom cameras (otherwise known as PTZ cameras), named for their ability to pan left and right, tilt up and down, and zoom in. PTZ cameras accomplish this through a unique combination of pan, tilt and zoom lens controls. The overall zoom capability of a PTZ camera is a combination of the digital and optical zoom values. Digital zoom uses electronics to zoom in and out, while optical zoom uses lens movement. The total value of the closeness of the video camera can be calculated by multiplying the digital and optical zoom... Camcorders require a keyboard and signal receiver to provide pan, tilt, and zoom capabilities. However, most PTZ dome cameras come with a built-in receiver.

Types of PTZ cameras

PTZ cameras are available for outdoor and indoor use, which adds to their versatility. Outdoor PTZ cameras have a rugged housing that is resistant to harsh weather conditions and are more reliable than indoor cameras. The reason for this is that they have to move a heavy case, sometimes equipped with IR illuminators. Indoor PTZ cameras are often made with plastic housings and are therefore lighter.

One of the most recent evolutions of PTZ cameras is the popular PTZ dome camera. Dome cameras work the same as traditional PTZ cameras, but differ in that the pan / tilt device and control electronics are located inside the dome. The range of domes is extremely varied, from transparent or translucent to opaque, making them suitable even for special applications. PTZ dome cameras have several advantages over traditional PTZ cameras. The dome can move effectively in all directions, including 360 degrees for straight down viewing. Dome cameras have an Auto-Flip function for viewing directly below it: when, upon reaching the mechanical stop, the camera unit automatically rotates 360 ° and continues in the direction selected by the operator.

PTZ Camera Features

In most PTZ cameras, algorithms can be created to automatically track from a given position along a specific route to continuously survey these areas. The number of preset positions varies depending on the make and model of the camera, but on average from 8 to 32. The ability of a camera to accurately return to a preset position differs depending on mechanics, electronics and software. In addition to presetting positions, PTZ cameras can be configured so that they only act in case of specific changes in the monitored area, for example, noise, movement. This is possible with the help of motion detectors built into the video camera or integrated with it. Thus, the recording process can be minimized and only for the most important events.

In addition, PTZ IP cameras can provide access to video viewing and camera control from anywhere in the world thanks to the ability to assign an IP address.

Another feature common to PTZ cameras is the ability to mask. This allows you to mask some areas in the camera's field of view, such as a window or door of a house. The position of the mask can be interconnected with the movement of the camera so that when the camera is tilted or scaled, the mask moves and resizes accordingly. This allows the user to avoid litigation for breach of privacy and invasion of privacy.

Photos before and after masking

Translated by Hi-Tech Security.