1. Introduction To expand production scale and improve technological level, the factory implemented a relocation and technological transformation project. The new factory area covers more than 1,000 acres and includes more than 20 buildings in production, office, and living areas. How to effectively protect the new factory area under construction and in operation is an urgent problem to be solved. Based on a site survey of the new factory site, this paper designs this security solution using Honeywell products. 2. System Functional Requirements This security system should provide real-time alarm protection for the entire factory perimeter and important factory buildings. After the system is armed, it should alarm and record video of unauthorized intruders; it should control access to important workshops and office areas, verify the identity of all entrants, record information, and record video. Therefore, the system needs to be divided into three subsystems: a digital video surveillance system, an access control system, and a burglar alarm system. These three subsystems should be combined into a complete system through a digital network to achieve protection of the factory area and important production and office areas. 3. System Overall Structure Design The factory security system consists of three subsystems: a digital video surveillance system, an access control system, and a burglar alarm system. The overall hierarchical structure of the system is shown in Figure 1. A certain number of cameras, access control devices, and alarms are installed at various important security locations within the factory area. These are connected to their respective field controllers via dedicated cables. The field controllers control the front-end equipment for security detection and control. The field controllers are connected to the monitoring center via the factory's local area network, uploading detection signals to the control computer host and server at the monitoring center for information display, storage, and corresponding management operations. Each subsystem is relatively independent and capable of performing its own functions; at the same time, the subsystems have linkage functions, cooperating and controlling each other to jointly achieve the security function. A monitoring center is set up in the security and fire control room of the joint workshop to realize centralized display and storage of video surveillance images and unified storage and management of access control management information and alarm information, and to achieve remote monitoring via the Internet. [align=center][img=397,320]http://www.ca800.com/uploadfile/maga/plc2008-1/lq-1.jpg[/img] Figure 1 Overall System Hierarchical Structure[/align] 3.1 Functional Design of Each Part (1) Monitoring Layer. The monitoring layer consists of a monitoring center video wall, a video browsing terminal, and an access control alarm client. The monitoring center video wall consists of eight 42-inch plasma monitors, which display images from cameras in the factory area. Each monitor can display a single screen and split four screens, and can display real-time images from 32 cameras simultaneously. With authorization, remote users can monitor images in real time and record playback through an IE browser, and control the front-end PTZ and lens. The access control alarm client is the management platform for access control and alarms. (2) Service Layer. The service layer consists of a video server, an access control alarm server, and a web server. The video server is mainly responsible for forwarding video information streams, sending control commands for PTZ and cameras, storing and serving video images, and supporting distributed management. The access control alarm server is mainly responsible for configuring the access control and alarm system, storing historical and real-time data of system image motion detection alarm, anti-theft alarm and access control usage information, and providing basic data for system query and analysis. The web server is mainly responsible for providing data access interface, video access interface and control access service for remote browsing terminal. (3) Control layer. The control layer consists of video encoder, access control controller and alarm controller. The video encoder mainly compresses and transmits the acquired images in MPEG-4 format, and controls the camera pan-tilt and lens zoom through pan-tilt decoder. The access control controller connects to field devices such as door lock, card reader and exit button, collects information from card reader and exit button, judges the access rights of the visitor according to the set program, and controls the opening and closing of door lock. The alarm controller connects to the dual-technology detector and buried leakage cable in the field, collects alarm signals of each defense zone, and stores and judges them. (4) Implementation layer. The implementation layer consists of on-site equipment, including various cameras, door locks, card readers, exit buttons, dual-technology detectors, and buried leaky cables, etc., to complete the acquisition of on-site video signals, alarm signals, and door status signals, and to control the cameras and door locks according to control commands. 3.2 Digital Video Surveillance System Digital video surveillance converts the analog image signals captured by cameras installed in various locations in the factory into digital image signals, and then transmits them through a computer network, so that all computers in the network can become monitoring terminals, without being limited by geographical environment, see Figure 2. Design a dedicated monitoring network, and achieve the security and high speed of the monitoring network through appropriate VLAN division. In addition, the signal transmission adopts the standard TCP/IP network protocol. The system mainly consists of three parts, see Table 1. [align=center] Figure 2 Digital Video Surveillance System Architecture[/align] (1) Monitoring front end. Includes analog cameras, pan-tilt units, decoders, and video encoders, etc., to realize image capture and on-site analog-to-digital conversion, and obtain digital image files based on the MPEG-4 compression standard. Depending on the different needs of users and the environment, additional protective covers, wipers, lightning arresters, etc. can be added. (2) Network communication platform. It consists of equipment such as switches, firewalls, and communication lines, and realizes the digital transmission of digital image files through the factory's local area network. It can also realize remote monitoring by authorized customers through the Internet. (3) Central control center management platform. The central control center management platform consists of monitoring host, video wall, monitoring management software, video server and database server. The monitoring management software EBI (Enterprise Buildings Integrator) is installed on the video server and provides complete monitoring center management, recording management, alarm management, user authentication and permission management, server cluster management and other functions. The database server is used to manage the database of the digital monitoring system, configure the entire digital monitoring system, manage all users of the system, and is the core management server of the digital monitoring system. 3.3 Access control system composition and function The access control system consists of controller, card reader, electric lock, exit button, identification card, management host and management software. Among them, the controller, card reader, electric lock, door opening switch and identification card constitute the basic access control unit equipment, as shown in Figure 3. The access control controller uses the Honeywell Star II controller, which employs an Intel i386-32-bit microprocessor chip, supports 50,000 identification cards, and features RS485, RS232, and optional 10BaseT Ethernet interfaces to meet communication needs with local card readers and servers. It is configured with 16 input points and 4 output points to connect to external devices such as door sensors, exit buttons, and electromagnetic locks to control their opening and closing. Communication between the access control controller and the card reader is via RS485, offering strong anti-interference capabilities, low sensitivity to temperature and humidity, and strong resistance to electromagnetic waves and lightning strikes. The communication distance can reach 1200 meters. [align=center]Figure 3 Access Control System Architecture[/align] The card reader used is the Honeywell DigiReader series, a key device for signal input in the access control system, used to read data from cards for fast and accurate identification. The main function of an IC card is as a data carrier, similar to a key, and serves as the user's ID card in the access control system. An electric lock is the locking component in the access control system. Different locks should be selected based on the door material, exit requirements, and other needs. 3.4 Design of the burglar alarm system: principle and selection of the alarm device. The alarm device is the front-end detection device of the burglar alarm system, used to determine whether any abnormal situation has occurred. Based on the advantages and disadvantages of different detectors, the DT7235T dual-technology detector is selected as the indoor alarm detector for the factory, and the TRX-100II buried induction cable is selected as the perimeter alarm detector for the factory area. [align=center] Figure 4 Dual-technology alarm detector[/align] (1) DT7235T dual-technology detector. Detection range: 11m x 11m, as shown in Figure 4; Sensitivity: 2-4 steps within the detection range; Microwave frequency: 24.125 GHz; Anti-tamper switch: 50 mA, 24 VDC; Alarm relay: Excitation type A (normally closed), 500 mA/30 VDC; White light interference: 6,500 lux; Anti-radiation interference: 30 V/m, 10 MHz ~ 1000 MHz [align=center] Figure 5 Functional diagram of buried induction cable[/align] (2) TRX-100 II type buried induction cable (as shown in Figure 5): Leakage cable installation spacing: 1-3 meters (1.5 meters recommended); Leakage cable installation depth: 3-20 cm (depending on the medium); Alarm method: contact; Maximum warning range length: 100 meters. [align=center] Figure 6 System software data flow diagram[/align] (3) Alarm host. Select Vista-120 series bus-based large alarm host. The host can be divided into 8 subsystems for independent monitoring, meaning each host can function as 8 separate hosts; it supports 150 user passwords at 7 levels, enabling multi-user control; it features time-based control, allowing for different user access settings or automatic functions (such as arming/disarming, relay switching, etc.) at different times; relay functionality: supporting 96 relays; and rich data interfaces, supporting data transmission via telephone lines, serial ports, and network interfaces. 4. Overall Implementation of System Software This system consists of three subsystems: video surveillance, access control, and burglar alarm, divided into a local monitoring system and a client system. It uses a client/server architecture, with application processing handled by the client and data access and transaction processing handled by the server. See Figure 6. The video surveillance system needs to monitor and manage a total of 151 cameras throughout the plant in real time. Given the large video stream volume, the amount of data processed and stored by the video surveillance system is substantial. A separate video surveillance software, Honeywell DVM (Digital Video Manager), is used to centrally store and manage digital video data. The video server acts as the server side, while the monitoring host in the monitoring center and other authorized users on the network act as the browser side. The access control and alarm systems are uniformly controlled by the access control and alarm server software. The video surveillance, access control, and alarm monitoring subsystems form a unified security monitoring system. The three systems operate independently yet are interconnected. 5. Conclusion This paper describes the overall system design, including three subsystems: a digital video surveillance system, an access control management system, and a burglar alarm system. These three subsystems operate independently yet are interconnected, forming a unified security system for the factory area. The field equipment underwent detailed design and selection. Through the conversion of corresponding network communication modules, analog signals from the field were converted into digital signals and connected to the factory's local area network. This meets the new factory's requirements for real-time protection and management, and is of great significance for ensuring the safety of factory property and the normal operation of production.