I. Introduction

With computer technology, communication technology, control technology, the field of information exchange is quickly covered the field plant devices, control and management of all levels, from the coverage section, workshops, factories, companies to market the whole world, so as to gradually form An enterprise information system based on integrated network automation systems. And now most of the factories of products from different manufacturers, several networks coexist, is difficult for many devices, networks, integrated operating protocols, which seriously reduces productivity, increases costs, reduces the ability to respond quickly. From bottom to top of a wide range of business automation requirements, world leader in automation Rockwell Automation has introduced a seamless integration of open architecture --NetLinx as a solution.

Today, industries, especially the automobile manufacturing industry, are facing serious challenges around the world. Full use of advanced automation technology and management methods, can improve the efficiency of the production cycle, to meet market demand, to stay ahead of the competition and maximize profits. Hunan Changfeng Motor Co., Ltd. (hereinafter referred to as Changfeng) is the largest light vehicle manufacturers off-road, cheetah automobile production currently occupy the country off-road vehicles more than 43% market share. However, with the continuous expansion of production scale, the presence in production management and logistics is increasingly important, has become a bottleneck hampering the development of the company. It has been used mature NetLinx open field bus network provides a link between high-level equipment and industrial equipment, control and coordinate the data collection control device and field information underlying the intermediate layer exchange, and a layer processing and with monitoring data communication Management is integrated and accessed as a subnet in other types of systems. system control and ERP system implementation in the production line of decision-making by the exchange of information managers, which will significantly improve systematic management, and increase market competitiveness.

Second, the NetLinx architecture

Rockwell Automation NetLinx open network technology developed using the integration of policies from the top to the factory floor, the main idea is organically combined with the network system and equipment for production monitoring, for the extended flow throughout the production process , and the use of other information in a network to connect the various plant plants, process control data and information easily and reliably in a PLC (programmable logic controller), Human Machine Interface (HMI), unit, FCS (field to be exchanged between the bus transfer control system), DCS (Distributed Control System), thus building a transparent, open automation system architecture.

Based on three NetLinx network layer: the information layer, control layer and a layer of the device. The structure of the system is shown in Figure 1 and the functions of each layer network are very clear.

Information layer. This layer uses the standard TCP / IP Ethernet protocol architecture, which provides the top-level computer system to access data via Ethernet workshop, mainly to the whole plant data collection system control, monitoring, management computing , statistics, equipment maintenance management, production processes and logistics tracking services, allowing open access computer databases using the SQL (Structured query) language. System administrators can system at this level network monitoring, to modify the program in the controller, causing the computer system to access the production site data to achieve the goal of real-time monitoring and PLC support. As a result of the TCP / IP protocol, it is possible to access the network easily control industrial to corporate local area network (Intranet), to achieve control systems and integrated ERP systems.

Control layer. It is intelligent and with a variety of control among the various exchange PLC data between control devices, coordination control, online programming and program maintenance, configuration, programming and troubleshooting remote device, you can also connect a variety of people Products of the machine interface are monitored. network control network called on this layer, using CIP protocol (Control and Information Protocol), and producer / customer (Producer / Consumer) mode

which allows all network nodes to simultaneously access the same data from a single data source and share data and information. The main control network to perform intelligent real-time control and high-speed I / S data networks and accurate data transfer function, which satisfies PLC processor connected, real-time high-performance information requirements HMI application , and other smart devices needed.

Layer of equipment. network equipment used at the device level, the underlying important industrial equipment is connected directly to the plant controller and to configure and monitor. This connection without the need for I / O modules, and can be collected in a convenient and fast realization of a large number of high speed data from the industrial field device, greatly reducing spinning. The network device is a flexible and open network, can provide manufacturers with more than 150 of the world's products are compatible.

NetLinx has notable advantages over other industrial control networks. It uses the structure of the Net (network) and Linx (open interfaces) composition, can be the most effectively implemented system configuration, data acquisition and control. Net which is the producer / consumer communication model, defines a series of super service agreement, which supports multicast, triggered-event, sending periodic triggering mechanism, is completely independent of network media, network media in different Configuration Layer control / field level bus technology equipment to use the information as the basis for field device information throughout the enterprise network, improve the information processing capacity and operational reliability of the control system to facilitate the user to configure , manage and maintain the system. This open field bus network integrates a variety of network services, network protocol using a common and open software interface to ensure the continuous transfer of information and control data flows.

Figure 1 NetLinx Architecture

It can be easily connected to the Intranet, Internet, making network inherently strong more powerful.

Third, the Changfeng logistics system

The biggest problem Changfeng appeared in the last production activities are opaque production information, production managers is difficult to know the circumstances of each workshop, since a part of the production of the problem, managers at all levels need to rely on several levels, after a very long time before it can be processed, resulting in a delay, or by the consequences of waiting in line in the production line, the production pace of the whole production line has reached chaos, the company has brought considerable losses. So now we try to control system and Changfeng ERP integration system (CF_C2I2), to collect production information management system to enable production managers to acquire each stage of production in the exact number of products and detailed product information in real time, Once production problems occur, they can be resolved in a timely manner. Throughout the production line of electronic Kanban, you can guide the assembly work in the production line and supply precise to pass information to suppliers through the Internet.

One type of kanban is to implement JIT pull (Just in Time, JIT) is a very effective means, since it is the Kanban production order, pick up instructions, shipping instructions to control the production operations plan and fine-tuning , achieve production Organize scientific management methods of high efficiency, high efficiency and cost-effective. Is based on the needs of the company as a whole, the production of the initial extraction point, according to the variety, quantity, time and place need time to organize all aspects of production, post-production process before the process it is just the variety and quantity to take, not overproduction, do not set up excess inventory, so that companies form a reverse and interconnected supply chain. electronic board is an information management technology and network conveyor board, which will process the production line of the plant directly reflected on the monitor screen, management staff may be required by the dynamic interaction the procurement of each object on the screen with the process of real-time information about WIP, monitoring the production site.

Changfeng's production process is divided into stamping, welding, painting, assembly, testing and other areas, which has to pull the starting point for final assembly Changfeng, all production processes are in order to the kanban withdrawal instructions, such as necessary after the production and distribution

to; the necessary information has been extended through the network upstream to the raw materials, suppliers and parts, the supplier according to the time of user lines required number and variety realization of production and transportation, the Association provided does not enter the user storage , Direct users to the point of consumption of the production line, thus reducing the inventory cost of each link. In the same time self-tuning function played by the placards of websites, flat together scheduling operations and logistics, reduce scheduling coordination difficulty and workload, improve the level of systematic management. NetLinx open network integration provides the most appropriate and reliable platform for JIT production.

Fourth, the integration of the management and control system

We will connect the key control network equipment Changfeng whole plant automation embedded in the management sub-network, which consists of open interconnection interoperability, interoperability, integrated network management and control, to achieve control systems and automatic ERP systems for exchange information.

4.1 Integrated Architecture Control Network

According to NetLinx architecture for a network of open automation architecture system, it needs to expand to meet the entire factory automation system, stable performance, easy to incorporate reliable information system, network management. The network system consists of three parts: within the workshop, using the device connected to the field network infrastructure equipment, which consists of the control of the underlying business network; network control supports the transmission of real-time data, connected to various devices such as PC, human-machine interface controllers, drag and a control device and other devices connected to the network; handled by the Ethernet network and information management systems link, such as in the network management structure of subcomponents communication, production management information transfer. This three-layer network can communicate with a PC and is conducive to real-time monitoring equipment and data collection with each other. Rockwell Automation provides industrial equipment with high compatibility, standard interfaces and internal communications capabilities, powerful software products provide very convenient for the application and use of Rockwell Automation ControlLogix control platform, which as a network control, routing and bridging Ethernet and DH + network, easily different communication protocols, data integration of devices from different manufacturers to the same platform.

Rockwell Automation provides user-friendly configuration, convenient and efficient graphical programming software, a simple, intuitive graphical information annotation symbols and to control user logic expression more intuitive, easy to use and operate. Use RSLinx (all communication scheme builder plant) to carry out the selection and configuration of the communication link according to the communication feature, a communication function provided at the factory floor level between the PLC and the device with a variety of applications software.

4.2 Implementation of monitoring and management functions

Software is the soul of the entire management and control system. --RSView32 used to dynamically monitor and control management information based HMI NT software. It will be presented under field conditions, the device process flow diagram, the trends on the screen, the operator control center to monitor the dynamic state of current at the production site and important plant operations, line process monitoring of production 2 painting workshop.

Figure 2 Production process in paint shop

Rockwell Automation's powerful industrial data delivery management software, RSSql, has a system architecture for distributed data collection, distributed database storage, and centralized delivery management, as well as transferring data in both directions. only at the control layer. The data is submitted to the enterprise-level database in the format required by the ERP system, and process equipment layer process data and control layer state information are conveniently integrated into the enterprise information tier database for decision making and release of management information; Extraction data from the ERP database is transmitted to the PLC and host computer of the control system.

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