New digital images long-distance centralized monitoring system

1. introduction

Information society, the technology is advancing rapidly.

With the continuous development of the national economy, power generation, hydrological investigation, television relay broadcast, and so on many occasions there is more equipment, more parameters for remote monitoring. Digital images long-distance centralized monitoring system is combined with advanced computer network technology, multimedia technology, communication technology adapted to the telecommunications, electricity, banking, transportation, water conservancy, and the diversification of public security, the user needs of digital video surveillance system-building programmes.

2. network

The system can be used for multipoint control system (MCU) for tandem Centre, using radiation forms and the monitoring point connections, through the monitoring point MCU on the image, voice and data, implementation of monitoring.

The entire system networking method has the advantage that the network structure is simple, convenient, flexible, rapid expansion of the connection. But the monitoring system requires a security, high reliability, stability, can transmit multimedia information, better scalability and compliance with international standards of network communication platform. Therefore, there are three points on the network. Ask network have greater bandwidth, higher source compression ratio. Network delay is small, the error rate is low. In order to meet the network transmission system of interactivity and flexibility of the development trend, the requirements for implementing multimedia monitoring and requires network support system makes it easy to extend and upgrade.

3. the principle of work

Digital image remote control system according to the different needs of users can be divided into low-rate system, high-rate system.

Low rate system available within video surveillance, 6B may be special line, ISDN, PSIN B-ISDN and DDN. High-rate system ensures image 6B ~ 30B, but requires monitoring 2M more bandwidth lines are used to transmit signals. Transmission mode: based on the physical transmission network of E1 transmission mode, high-speed, fiber optic, wireless microwave, hyper-v class above twisted pair and renting public network 2M lines etc.

As shown in Figure 1, smoke, fume and so on the detector will capture the analog signal to A/D converter, converter converted the digital signal is sent to the RS232 or RS485 transmission for image encoding.

The monitoring center to each branch control center respectable multipoint controller, via DDN/ISDN/E1/MW, transmission connection solutions for encoder.

Center codec output video signal enters the screen processor. After its split output multi-channel video signal sent to the TV wall or management platform. Video switch that picture processing equipment will terminal of the camera capture to image in a certain time interval, were transferred to the image encoding transmission equipment. The device will graphics in accordance with a certain algorithm to encode, compress, the DDN/ISDN/E1/MW, and other lines to multipoint controller (MCU). MCU similar a small switch, it can provide multiple ports for each child control unit multi monitor signal access, and in accordance with a certain algorithm for audio streaming, video streaming, data flow processing. MCU will these signal matrix switch to a parent control center, data gathering processor¡ ¢ CCTV or codec to CRT.

LAN Ethernet or FDDI may be used, and other forms of networking.

Data gathering processor¡ will send by MCU signal is decoded and released to the LAN. Control Center or child supervision Center can achieve and local MIS network or other network-friendly connection. Local MIS users can identify the permissions to access the server through the video monitoring system acquisition to the video signal. Video Server main role is to video on demand (VOD), while enabling Internet users to access management and video video access provisioning management. This system video server is responsible for the whole network of intelligent information processing work, through modular design realizing multiple processors work together. User accessible over the network, on-demand video of the video programs on the server. Typically, you can choose to apply to a small or medium-sized network video server, the user number 0 ~ 50 or 50 ~ 1000. Video server to respond to users on demand, video to video stream transmission to each workstation computer. This individual workstations can be browsed, send the command (such as: the camera turn left 50 °, vertical drop 2 cm). The command compiles the software, in LAN transmission sent to decode for encoder, then by MCU switch, fibre and other transmission line to the image encoding transmission equipment. The device will command interpreted as control signal sent to the head, and command the camera work, which enables remote monitoring.

4. concluding remarks

Digital images long-distance centralized monitoring system is a new monitoring system, which breaking the traditional limitations of the CCTV system, to coordinate the different equipment needs, ensure seamless communications, resolve the video, audio, digital signal transmission on the network.

This new kind of interactive multimedia monitoring system will be gradually penetrate into production, all aspects of life. As the network technology, communication technology and video on demand technology and mature, it will be widely applied.