Wireless industrial control solution Although the harsh industrial environment has always been a barrier to the application of wireless technology, there have been new breakthroughs in the past 10 years, and many enterprises and engineering technicians in the world have worked diligently to explore new prospects for industrial automation using wireless technology. In July 6th, in Shanghai, the Professional Committee of Instrumentation and Devices of the Chinese Society of Automation, the Professional Committee of Automation Application of the Shanghai Society of Automation, and the Professional Commissioner of Automation Instrumentation and Application of the Shanghai Society of Automation were held in the Science Hall to "The third technical forum for experts in the field of automation. More than 60 people including Professor Qinwei Wu, former director of Shanghai Industrial Automation Instrumentation Institute, Professor He Guosen, Shanghai University, and Zhonglin Tian, ​​former Sinopec Shanghai Petrochemical Research Institute, attended the meeting. There were 5 experts who made the keynote report: Professor Peng Yu of Shanghai Industrial Automation Instrumentation Research "Advanced Application Analysis of Wireless Short-range Networks and Wireless Local Area Networks in Factory Automation and Process Automation", and "ZigBee" by Professor Ling Zhihao of East China University of Science and Technology "Technical Support and Application Prospects", "Industrial Wireless Local Area Network Siemens Solutions and Application Examples" by Engineer Zhang Huiliang of Siemens (China) Co., Ltd. Shanghai Branch, and "Industrial Wireless Communication Technology at Shanghai General Motors Corporation" by Shanghai General Motors Corporation "Application", Senior Engineer Ji Gang of Shanghai Tongxin Automation Instrumentation Co., Ltd. "Application of Mobile Communication Technology in Energy Spring Data Acquisition System". The meeting was chaired by Professor Wu Qinqin and Mr. Peng Yu of East China University of Science and Technology. A development trend 1. Technology is developing Wireless network technology can be divided into: WWAN (wireless wide area network, IEEE802.22), WMAA (wireless area network, IEEE802.20, 802.16), WLAN (wireless local area network, IEEE802.11), WPAN (wireless domain) Network / short-range network, IEEE802.15). What wireless systems are around us? Regarding the new technology ZigBee that the industrial control community pays attention to, Mr. Ling Zhizhe introduced that it is a low complexity, low power consumption, low data rate, low cost wireless network technology, which is mainly used for short-range wireless connection and can be connected in theory. There are as many as 65,000 nodes, with 2.4GHz ISM frequency band, 868MHz frequency band in Europe and 915MHz frequency band in the United States. The channels available for different frequency bands are 16, 1, 10 respectively. ZigBee is not completely equivalent to IEEE802.15.4, which only deals with physical layer (PHY) and media access control (MAL) layer protocols, while ZigBee Alliance standardizes its network layer and application layer protocols, and the user layer is user-defined . The PHY layer uses Direct Sequence Spread Spectrum (DSSS) technology to divide a signal into multiple signals in a round-to-zero manner, and then transmits the signal through a coding method to avoid interference. In the MAC layer, the CSMA / CA method of IEEE802.11 series standards in WLAN is mainly used to improve the compatibility of the system. At present, the world's manufacturers that can provide ZigBee software and hardware products are: (1) In terms of hardware: Norwegian semiconductor company Chipcon has launched the world's first 2.4GHz RF transceiver chip CC2420 (with AtmelAVR 8 bit microprocessing) After the device), in the third quarter of 2005, another system chip (SOC) model CC2430 was launched, which included RF, micro-processing, and memory, which greatly reduced the cost of future ZigBee related products and simplified the design product cycle. Motorola's subsidiary Freescale also introduced 2.4GHz RF chips with three models: MC13191, MC13192, and MC13193. (2) In terms of software: International companies such as Ember, AirBee, Figure 8 Wireless (F8W), etc. can provide ZigBee software. The Z-stack of F8W, which has been acquired by chipcon, is an important part of the ZigBee suite of software developed by it, making Chipcon a supplier of ZigBee complete solutions. Freescale is also a Z-stack with F8W. In this way, the two ZigBee chips plus Z-stack have become the gold platform for certification of ZigBee products. At present, only products that have such platforms, comply with the 801.15.4 protocol, and have been evaluated by the ZigBee Alliance can be labeled with ZigBee products. 2. Standards are being developed IEEE has formulated a series of general software protocols related to network, security, and applications for different wireless communication technologies. Now, some international organizations are considering formulating industrial standards. Mr. Peng Yu said that the ISP SP100 Standards Committee of the American Society of Instrumentation, Systems and Automation (ISA) is stepping up the development of standards for wireless systems in automation and control environments. The plan focuses on formulating standards from three aspects: the environment using wireless technology, the life cycle of wireless communication devices and systems, and the application of wireless technology. SP100 will apply existing standards as much as possible (such as ISA SP99-information security, IEEE1451-smart sensors, 7-layer model of ISO / OSI network interconnection, etc.) and improve it to strive to promote the development of new technologies And the reasonable deployment of wireless network nodes and applications to ensure the benefit of suppliers and users. Mr. Peng Yu introduced that in order to enable wireless product suppliers to have consistent specifications, ISA SP100 now stipulates 6 types of applications in the automation and control environment: Type 0 (security type): Hengwei ’s critical emergency actions, including safety Lock emergency stop, automatic fire control, etc .; category 1 (control category): critical closed-loop regulation control, generally all critical loops, such as direct control of field actuators, frequent cascade control, etc .; category 2 (control category) ): Frequent non-critical closed-loop frequency monitoring control, multivariable control, optimization control, etc .; category 3 (control category): open-loop control, which means that someone is playing a role in the loop; category 4 (monitoring and monitoring category) : Marking produces short-term operation results, refers to messages that wirelessly transmit data that only produces operation results in a short time; Category 5 (Monitoring and Monitoring): recording and downloading / uploading do not produce direct operation results, such as historical data Collection, periodic collection of data that must be performed for preventive maintenance, uploading of event sequence record (SOE) data, etc. The chief technology officer of BP pointed out that the actual application demand for these categories (excluding category 0) is roughly 1: 2: 4: 10: 10. It can be seen that in the automation and control environment, the application of wireless communication technology mostly belongs to categories 3 to 5. 3. Manufacturers are working hard In order to meet the needs of the wireless industrial control potential market, manufacturers have done a lot of experimental research and development work. In this regard, Mr. Peng Yu gave a detailed introduction: (1) European wireless industrial control application project (RONES) From October 2004 to April 2005, 25 European organizations (including large and small companies and research institutes) developed a development roadmap called RONES that will develop and apply wireless technology in industrial control and automation in the next 10 years. They believe that wireless networks create opportunities for the high flexibility and cost advantages of industrial system installation and operation, and opportunities should be seized in a timely and solid manner. The goal is to reduce installation costs by 50% and operating costs by 30% by 2008 using wireless technology; reduce installation costs by 80% and operating costs by 50% by 2014. (2) Wireless HART protocol is being actively developed According to ARC statistics, there are currently more than 40 million field instruments installed in the world, of which about 48% use 4 ~ 20mA signals, about 26% use HART, about 13% use pneumatic signals, and only 1 using fieldbus %. Therefore, the decision of the HART Foundation (HCF) to develop the wireless HART protocol is of great significance. The wireless working group has been established and is developing technical specifications. The goal is: the wireless HART protocol should have all the applications that can be solved by the current wired HART protocol to meet the SP100 regulations. All application requirements of category 0 ~ 5. The working group had considered adopting ZigBee, but after reviewing all the technical requirements of wireless HART, it decided not to adopt it. This is the low power consumption of National Grey ZigBee's RFD (Simple Function Device) and cannot deal with the routing problem of the mesh network. For this problem, each node must be in a continuous working state and cannot sleep, so that the power consumption is large, and it is difficult to achieve low power consumption. The original plan was to formulate the wireless HART specification in June this year. At present, we have not received the specification document (Shanghai Industrial Automation Instrumentation Institute participates in HCF). (3) Honeywell and other companies launch wireless industrial control products In 2003, Honeywell launched the XYR5000 series of transmitters using ZigBee wireless network technology. It includes equipment for accurately monitoring pressure, absolute pressure, temperature, ultrasonic noise, and steam and gas leakage. This series of products also has analog input interfaces to enable wired devices With the ability to work wirelessly, each base station radio station connected to the control system or data acquisition device can receive wireless signals transmitted by up to 50 transmitters. In 2004, the US Department of Energy (DOE) invested US $ 10 million and signed a contract with Honeywell to continue to develop XYR5000. DOE hopes to use this technology to reduce runoff and drip in steel, electrolytic aluminum and other six industries, and reduce energy consumption by 15 %, And reach the harsh industrial control application level: XYR5000 is suitable for automatic control in hazardous areas, remote control, and locations that are difficult for people to touch. At present, the carrier frequency of this product is 915MHz, which is only suitable for use in the United States, and there is no 2.4GHz product suitable for global use. OMRON has launched a master station WD30-ME and a slave station WD30-SE that wirelessly connect to the DeviceNet fieldbus. It can support up to 1600 points of DI / DO communication, and has been successfully used in the control system of Honda's assembly line. The German SchildKnecht company launched the wireless Profibus-DP product DE3000 series, which can establish a wireless link between the master station and multiple slave stations. It uses a carrier frequency of 2.4GHz and a data packet of 187.5kB. They are WLAN (IEEE802.11b, 11Mb / s, 802.11, 1Mb / s) and WPAN (802.15.1, 700kb / s). (4) ABB and other companies conduct field device layer wireless communication experiments ABB's Boliden processing plant in Sweden used Ember's wireless technology to conduct wireless communication evaluation tests. The requirements are: transmission of non-process critical data, short data packets, low average data rate, and low power consumption through wireless communication. Specific applications include: equipment management, condition detection, preventive maintenance, and service applications. The results prove that ZigBee satisfies the application requirements of the open-loop system; however, ZigBee's existing technology has problems in closed-loop control. BP has conducted many wireless application experiments, and the results prove that wireless mesh networks (Motes) can bring great benefits to BP. But most of BP's industrial sites require intrinsically safe equipment, and intrinsically safe wireless industrial control products are currently not available in the world. (5) Invensys announced its wireless communication strategy in industrial applications The strategy is to achieve its application requirements by establishing a unique and extensive management network, that is, focusing on the use of shared access point technology for all wireless devices, and using a common data and information security model for all wireless frequencies and communication protocols. The purpose of this strategy is to provide an appropriate level of integration, robustness, and basic assurance of information security for wireless applications in all industries and enterprises. The wireless application solutions that Invensys expects (not considering SP100's category 0 and category 1 applications) include: process optimization, equipment management, real-time device status monitoring, energy management, personnel tracking, and enterprise management. Invensys is currently conducting on-site surveys of several large chemical enterprise groups in North America. If the wireless network strategy it researches is realized, it will enable users to significantly save costs and allow data obtained through wireless networks to be easily integrated with asset management software. The standardized security model helps to effectively manage the wireless network and keep it at an appropriate level of information security and performance. Two application cases 1. Siemens case Mr. Zhang Huiliang introduced that Siemens wireless products combined with wired distributed I / O, Profibus, PROFInet, PCS7 system and other products have solved the industrial control problems of some special conditions, such as the cable crane transmission system of the Yangtze River Xiangjiaba Hydropower Station. Transmission requires the installation of long-distance cables above the Yangtze River. Now it is convenient and cost-effective to adopt a wireless transmission system. Siemens' wireless industrial control solution has also been applied to the Yuanbaoshan Coal Mine's raw coal transportation system, some three-dimensional garage control systems, and dock cargo lifting systems. Siemens' wireless products are mainly in the following categories: (1) Wireless access point module: The product has SCALANCE W788-1 / W788-2, which is equivalent to a switch and is used to build a wireless local area network. (2) Wireless client module: The product has SCALANCE W744-1 / 746-1 / 747-1, which is used to connect PLC and other devices to the wireless local area network. These two types of products support the WLAN standard IEEE.11a / b / g; the operating frequency is 2.4GHz or 5GHz, and the data rate is up to 54Mb / s; because the data rate of key nodes can be effectively guaranteed, it has high reliability; because Using WPA and 128-bit encoding encryption technology (AES), which can prevent illegal operations and high security; provide configuration support through security wizards and online help; due to the use of detachable C-plug (configuration plug-in), it occurs Can be quickly replaced in case of failure. (3) Accessories: such as directional antennas, quick connectors, etc., among which IWLAN / PB Link PN I / O is a mobile accessory that provides a compact network interface between Industrial Wireless Local Area Network (IWLAN) and Profibus. PROFInet I / O proxy products allow flexible connection of Profibus-DP slave stations to PROFInet I / O controllers via IWLAN wireless communication infrastructure, which ensures communication between mobile devices and automation systems, such as vehicle systems, three-dimensional warehouses Or trolley monorail conveyor system, etc. (4) Software: Provide various supports and services. Mr. Zhang Huiliang also introduced that Siemens has conducted research on the use of industrial wireless local area network technology in industrial environments. About 80% of customers are concerned about the three major issues of reliability, ruggedness, and security. Siemens wireless products meet these three requirements. Siemens' wireless products also have other features, such as a fast roaming function, which can shorten the pickup time when used in large warehouses. When industrial sites such as workshops and warehouses are large and there are many items, wireless communication is often interfered and blocked. At this time, only one antenna is active and coverage is not large. The cost of using multiple fixed antennas is high. Siemens has a leak antenna It can be bent, can solve this problem, and the cost is greatly reduced. 2. Shanghai General Motors (SGM) case SGM currently has three major production bases in Shanghai, Jinqiao, Yantai, and Shenyang, with an annual production capacity of 480,000 units. A large number of computer control technologies are used in production and management. Among them, the industrial wireless technologies used are: IEEE802.11b, ANSI371.1 and Siemens Wireless products, etc. The SGM wireless application system mainly has the following 5 categories: (1) RF-Electronic Handling System (RF--EPS): When on-site workers need materials, press the wireless button to send a signal to the material request indicator board, where the forklift driver waiting in line to pick up the materials to the parts warehouse The scene needed. (2) Portable program test tip (PPTH): used to refresh the program of the electronic control module (ECU) on the complete vehicle of the assembly line of the assembly shop. (3) Automatic mobile car (AGV): The main PLC collects the data and status parameters of the AGV car, performs calculations and then sends the corresponding commands to the AGV, which travels according to the direction and route of the main PLC commands. (4) Global customer review (GCA) system: The quality department staff asks customers to perform quality inspections on manufactured vehicles, and uses wireless handheld roadside review while inputting the review results to the system to provide the required quality data for each business department . (5) Automatic vehicle identification (AVI) system: It can identify and track vehicles in the body shop, oil painting workshop and body distribution center, including the number, model, color, etc. MOBY used-intelligent identification based on radio frequency technology The system is also a Siemens product. (6) Body Distribution Center (BDC). SGM is currently working on wireless industrial control projects: Guangzhou and other 3 spare parts warehouses for wireless management. 3. Case of Shanghai Tongxin Company According to Mr. Ji Gang, Shanghai Tongxin Automation Instrumentation Co., Ltd. has adopted the following two kinds of wireless industrial control schemes in engineering projects such as the online deployment management system of a thermal power plant heat network in Shanghai, the Energy Spring Center of Pudong International Airport, Jiangsu Yancheng Thermal Power Co., Ltd. and other projects: (1) SMS-based data collection and monitoring system: This is a widely used information system. It uses mobile communication technology to connect computers and mobile phones with remote measurement instruments to achieve remote data collection and monitoring (SCADA). You can use the mobile phone to read and monitor the measuring instruments at any location and at any distance. Remote data, alarms and status information can be transmitted to N places at any distance for simultaneous display. The SMS short message service uses a store-and-forward mechanism to work, with low cost and reliable transmission, and is suitable for application objects with low real-time requirements. (2) GPRS-based data acquisition system: This system adopts a modular structure. According to the general requirements of users, it can be composed of 5 major modules, namely system settings, data display, data query, data curve and data output. The working principle is: the computer sends a request to the GPRS wireless measurement and control unit through the Internet and GSM network according to the detection point station number set by the system through the Internet and GSM network, and calls the specific detection point universal flow calculator (FC-6000plus) Pack the data according to Modbus RTU mode, and then send the communication message back to the GSM network through the GPRS wireless measurement and control unit, and send it to the connected computer via the Internet. The computer performs CRC check processing on the recovered data, displays relevant information, and has a report Production, display and printing functions. Three points of view (1) Mr. Peng Yu believes that the wireless technology of industrial control is mainly concentrated in the two directions of wireless local area network and wireless short-range network. Although they have a fairly solid and mature technical foundation, in order to adapt to the requirements and environment of industrial control, special Development research. In addition, because the advantages of wireless field instruments must be reflected in long-term wireless power supply, generally speaking, wireless transmission is not suitable for high-speed control occasions. But practice has proved that it is reliable enough for most monitoring and slow-speed control occasions, which means that it can be used in nearly 80% of automation and process control occasions. (2) Mr. Ling Zhihao believes that although ZigBee is concerned by the industrial control community, there are still some problems in the application of industrial control that are worthy of study. For example, in the case of uncertain node positions, the network needs to have self-organizing and self-healing functions; For a large number of nodes, how to reasonably schedule so that the resulting router path is reasonably effective; there are national frequency hopping technologies and anti-interference technologies that require further research and discussion. (3) Through discussion, everyone thinks that wireless communication should be regarded as a development and an important supplement to the existing wired communication system, and it is by no means an alternative. Due to the immaturity of field device-level wireless network technology, wired transmission should still be used for tasks with high real-time requirements and strict requirements. At present, wireless industrial control still has a lot of work to do in terms of high reliability, low cost and low energy consumption. High Power Light,Led High Power Lamp,High Power Led Light,Led High Power Lamp Price Changxing Fanya Lighting Co.,Ltd , https://www.fyledlights.com
The keynote report of this meeting fully reflected some of the major technologies and solutions for wireless communication in the field of industrial control in the world. The discussion was also very lively. Due to space limitations, this article only reflects the wonderful aspects of the meeting from the following three aspects.
Mr. Peng Yu introduced that some of the wireless transmission technologies being developed include: wireless switching technology, mesh network technology and smart antennas. Some of the wireless transmission standards that are being developed are: (1) ZigBee (IEEE802.15.4): it has a very long battery life, which is very suitable for industrial automation, household appliances and sensor network applications; (2) ultra-wideband (UWB, IEEE802.15.3a , 802.15.4a): The United States Federal Communications Commission (FCC) opened its free broadband frequency range without application for 3.1 ~ 10.6GHz, without RF carrier, low cost, low power consumption, non-linear transmission, in low transmission rate mode, Can be used in an important industrial market-location awareness (within 2cm ~ 20m); (3) WiMax (IEEE802.16, proposed by Intel): suitable for long-distance (≥1km) RF in residential areas / operating buildings The link has a higher data transmission rate (about 70mb / s in a 20MHz channel) and can also be used for large-scale industrial deployments. Commodities will be available this year.