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This system is a new monitoring system based on TCP/IP network, using standard IP packets for image, sound and control data transmission. Its core technology is IP multicast technology. Therefore, the design, installation, operation and maintenance of the network are Previous image. There are major differences in monitoring systems.
1 System Design This system is divided into three parts: image acquisition and site monitoring, network transmission, and monitoring center monitoring and maintenance according to the location of the equipment and control software. Among them, the design of the image acquisition part is the same as the traditional monitoring system. The key point of this system is the design of the IP network.
1.1 Camera, PTZ, and lens According to the actual situation of Heshan Power Bureau substation, do the following configuration:
a. Each station is equipped with 1 to 4 sets of 8x16 times Pelco integrated high-speed ball and 1 to 2 sets of 16x color camera with pan/tilt head, with 3 variable lenses.
b. The integrated high-speed ball is installed on the roof of the building. It is mainly used for monitoring main transformers and scanning a large area. Cameras are installed in the main control room, high and low voltage rooms, and communications room.
c. Fixed-camera guns and wide-angle lenses are required in places where wide viewing angles are required.
d. Infrared probes are installed at the gates of the substation and the surrounding walls.
1.2 Field Control Matrix The basic configuration of the monitoring matrix is ​​32 inputs and 8 outputs, but it has good expandability and can be expanded to 64 channels to fully meet the needs of substations. Therefore, if you need to add cameras in the future, you can easily join the system.
The monitoring matrix also has an alarm interface. In the initial stage, the infrared detector's alarm output is sent to the monitoring matrix and sent from the monitoring matrix to the monitoring center. After the monitoring center processes the alarm, it can respond to the alarm event by voice.
1.3 Video Front-End Unit The video front-end unit uses the standard -48V communication power supply, so it is possible to use the backup power supply of the communication room. In the event that the 220V power supply is abnormal, it can ensure the normal operation of the video front-end unit.
The front-end machine compresses and packs the video signal after transmission in a hardware-compressed manner. At the same time, it accepts commands from the monitoring center to perform image switching control on the matrix, collects alarm information, and passes the matrix to the intelligent high-speed ball, head, lens, and camera. Lights and other controls.
1.410Base-T/G.703 Converter This system uses a monitoring center as the connection center to form a star network topology. The basic network channel is a standard Ethernet and the transmission channel is E1. At the station end, the lOBase-T/G.703 converter from Telindus of Belgium automatically converts the Ethernet data packets to E1 for transmission. At the local office, it is converted back to standard Ethernet data packets. The Telindus converter works on the second floor as a transparent bridge. Therefore, both the station and the monitoring center are on the same LAN. The converter also supports the routing method. However, in order to make the network simple, reliable, and easy to maintain, it is still allowed to work in the transparent bridge mode.
1.5 Monitoring Center The monitoring center computer is used to communicate with the on-site host and process video signals. At the time of design, the lOBase-T/G.703 converter is used in the central control room to send the signal from the optical transceiver directly to the network of the monitoring center.
Taking into account the independence and stability of the ESC system, the local area network of the monitoring center should be an independent network and be connected to the MIS network of the Heshan Power Bureau through a fiber channel. In order to continue to ensure the independence and stability of the monitoring network and not allow the video stream to affect the MIS network, the monitoring network must be placed in a separate VLAN. Due to the large number of video streams to be processed and the requirement to support IP multicasting, the Cisco Catalyst 3524 was chosen as the switch in the monitoring center. The Heshan Power Bureau central switch is a Cisco Catalyst 6509, high-performance, and supports IP multicast.
Calculate the performance requirements for switches and routers below. According to the VCD standard, the video bitstream is 1150 kbit/s, ie, 144 kB/s, and one video UDP is about 1.OkB to 1.5 kB. Therefore, the maximum number of UDP packets per second per video is 150. In this way, the demand for the packet forwarding capability of the 10-channel video to the switch is 1500 per second.
In this system, Cisco Catalyst3524 has 10Gbit/s switching backplane, 6.5X106 packets per second forwarding capacity, more than enough for 10-channel video processing.
2 Configuration of the switch One of the keys of this system is the configuration of the network switch.
According to the design, the monitoring center's switch Cisco Catalyst 3524 is not divided into VLANs, the central office switch Cisco Catalyst 6509 is divided into a separate monitoring VLAN, the port member is the fiber port to connect the Cisco Catalyst3524.
Between the Cisco Catalyst 3524 and the 6509, Cisco's proprietary multicast group management protocol, CGMP, is implemented. Therefore, configuring the Cisco Catalyst3524 requires only the opening of CGMP:
Setcgmpenableandsetcgmpleaveenable
The configuration of the Cisco Catalyst 6509 has two scenarios: the transmission and non-transmission of video streams to the Heshan Power Bureau MIS network. The difference is whether the multicast routing feature is configured in global mode:
Ipmulticast-routing
Only the CGMP and PIM need to be configured on the fiber ports connected between the Cisco Catalyst 6509 and the 3524:
Ippimdense—mode
Ipcgmp
In this configuration, the Cisco Catalyst 3524 and the 6509 forward or duplicate only the video streams that a client needs, without affecting other ports that are not participating in monitoring.
It must be noted that the use of IP multicast must have a router to maintain the multicast tree. Otherwise, the IP multicast packets will only be broadcast in LAN switches.
3 System Expansion After the installation of the system is complete, the system is continuously expanded and software upgraded according to actual needs.
a. The number of substations can be expanded: the monitoring center uses 10Base-T/G.703 converters. If one substation needs to be added, only one converter can be added: one at the station end and the other at the control center. The connection of the converter is very simple, just l network cable, no configuration.
b. The number of clients can be expanded: only one set of client software needs to be installed, and any multimedia computer on the network can be used as a client.
c. The number of camera guns at the station can be expanded: the monitor matrix can be expanded to 64 inputs and can accept up to 64 camera guns.
d. The control function of the monitoring matrix can be extended: in addition to the infrared sensor, it can be connected to smoke, temperature, and control lights, air conditioning and so on.
4 Operation This system is a remote digital video surveillance system based on IP transmission mode. It adopts IP multicast technology and conforms to TCP/IP network communication protocol. It can be established by various transmission lines such as microwave, xDSL, DDN, ATM, SDH and so on. Running on an IP network, the monitoring terminal is an ordinary multimedia PC. Video data encoding and decoding and compression using MPEG-1 standard.
This system has real-time image monitoring, video switching and round robin, pan/tilt, lens, wiper, light control, screen segmentation, alarm linkage, electronic map, arming and disarming, hard disk video recording and playback, system log and record query, site and user management. , permission and priority settings, two-way voice intercom and conference calls, and system self-diagnosis and remote restart and other functions.
The system has the following features:
a. The use of advanced IP multicast technology reduces bandwidth consumption, impact on IP networks and reliance on video front-end performance.
b. Supports standard IP networks, theoretically supports stepless networking, and any IP network can be monitored anywhere.
c. The use of advanced and mature MPEG-1 video compression technology ensures the real-time and clarity of video data transmission.
d. It can be monitored in real time. Under the condition of ensuring 352X288 resolution, the number of image frames reaches 25 frames/s.
e. At the same time, hardware and software interfaces are provided to enable interconnection with other systems such as fire alarm systems and dispatch telemetry systems.
f. Provides VolP voice intercom and web conference phone functions, eliminating the need for additional bandwidth and additional cabling.
g. System software is based on Win9x/Win2000 platform, all Chinese interface, simple operation, intuitive interface, complete functions.
h. Due to the standard based IP network. Therefore, it is highly scalable and maintainable.
i. It is highly scalable and can be upgraded to MPEG-2 and MPEG-4 by replacing the video capture code compression card and monitoring software, thereby protecting the user's investment.
j. Designed for the substation application environment, it has strong resistance to strong electric fields, strong magnetic fields and other anti-jamming capabilities, and is suitable for substations and other occasions.
The system performance index is:
a. Image transmission frame rate transmission rate: no less than 25 frames/s, video data transmission rate: 1150 kbit/s
b. Image Resolution: CIF format (resolution 352x288)
c. Computer display resolution: more than 800x600;
d. Average computer CPU load rate: less than 30%
e. System response time: The time difference between the control command sent from the monitoring terminal and the screen response is less than 1.2s; the time difference from the event alarm to the system automatically switching and recording the corresponding screen is less than 1s.
Chillers are also known as: chillers, refrigeration units, ice chillers, cooling equipment, etc. Because of the wide range of uses in various industries, the requirements for chillers are also different. Its working principle is a multifunctional machine that removes liquid vapor through compression or heat absorption refrigeration cycles.
Design and Operation of Substation Remote Viewing System
Introduction Heshan Power Bureau substation remote image monitoring system (abbreviated as this system) was installed and commissioned in July 2001. It started with three stations. In October 2001, it was expanded to 10 stations. A substation remote image monitoring network has been formed. .
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