Saturday, September 25, 2010

FreeBSD Serial (35): serial port and modem

LAN to FreeBSD and Internet (or other wide area network) connection, you need to use the wide area network interface. For the average user, using ordinary telephone lines for dial-up way, it is more common practice. This requires first to use the computer's serial port to connect to the modem (modem), the further through the modem to connect to the Internet.

Serial port and modem

So if using a computer dial-up connection to the remote, you must configure the computer's serial port and a good modem.

Personal computers generally have two serial ports, DOS, called COM1, COM2, FreeBSD Unix habit of using the array starting from 0, corresponding to the serial port hardware sio0, sio1. Start the system will automatically detect the hardware, test results appear on the screen, you can log in to use dmesg to see the startup information to determine whether the hardware actually being detected. If the serial port is detected, you can use to connect to the appropriate serial port on the external modem to connect.

If you use the built-in modem card, the card will include a serial device, according to the card's settings, the serial device can sio2 or sio3, we must ensure that the kernel support for the third, fourth serial devices sio2 and sio3. But with the DOS is different, modem cards can not be used with existing serial port IRQ sharing hardware resources. Since DOS is a single task operating system, can not use both serial ports, IRQ sharing is possible, therefore COM1 and COM3 share IRQ 4, COM2 and COM4 share IRQ 3. But for multi-user operating system, FreeBSD is concerned, there will be multiple processes simultaneously access devices, each device must occupy a separate IRQ, it is necessary modem cards in the kernel will set another free IRQ value.

To change the jumpers on the card or run the Setup program in DOS, change the card settings to make the hardware settings are consistent with the kernel configuration. PNP modem card is usually the correct set of hardware resources can also be reset by UserConfig.

When the FreeBSD kernel detects serial device, the device will be able to file through the corresponding access the serial port of the. Corresponding to the first serial device sio0 documents / dev/ttyd0 and / dev/cuaa0, corresponding to the second serial port sio2 device file / dev / tty d1 and / dev/cuaa1, and so on.

FreeBSD provides two serial ports on a device file, in fact, they correspond to the same hardware, only slightly different properties. cuaa0 mainly used to allocate, ttyd0 mainly used to dial and direct connection. Setting these two devices as the reason for a computer and modem to communicate data between two categories, one for the computer to the modem through the serial port to send control commands, used for the AT commands Hayes, the data is sent to the modem, but another computer via modem to send data to the telephone line transmission data, which only you can let the modem to modem. For the application in terms of, to a very simple to distinguish between the two data, the initial state can use two different devices file.

When an external dial-house, the telephone connection has been set up, and data transmission is between the computer and telephone network, modem to modem only, this time on the use of ttyd0. When the outward dialing, modem not establish a connection, the computer should send the command to the modem, control the implementation of dial-up modem, etc, then use the device file on cuaa0. Once the connection is established, the system will reset the device file's properties, making cuaa0 data is also sent to the phone line.

So ttyd0 and cuaa0 two device files, but different initial conditions, and are not essential differences. In fact most of the dial-up software will reset the device file of the state, which device to use dial-up process can be completed properly. However, the practice is still customary to use cuaa0 to set aside, ttyd0 as a dial, so to avoid some of the software can not correctly reset the device file of the state of the problem.

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Tuesday, September 14, 2010

Green Manufacturing MES successes

Manufacturing Execution System MES (Manufacturing Execution System) is the integrated processing core technology, its main function is responsible for the implementation of production management and scheduling. In the integrated 璇稿 quality control, document management, production scheduling function on the basis, MES for the control Baokuo materials, equipment, Ren Yuan, Liu Cheng instructions and Sheshi including the Suoyougongchang resources to provide a Tongyipingtai, pairs the efficiency of raising productivity, improve product quality, reduce consumption plays an important role.

Although not as well known to the public as ERP, MES is also a manufacturing information, especially in the core technology of process industry automation, MES in the enterprise project management and plant production control information between the erecting of a bridge of communication and management to enable enterprises to it will be easier to establish a rapid response, flexibility, fine, uniform information manufacturing environment to help companies improve product quality and the environment, reduce material and human and other resources consumption.

MES into the industrial stage

Such a product in terms of steel, quality of design and control is very important and must be carried out from the start. On the production line of smelting, rolling, finishing and packaging and other procedures for the consistent quality of design, but also with the production process data and performance data to determine the production-line real-time exception occurred during the quality. Through the support of 863 projects, Shanghai Baosight Inc. launched Baosight MES products and the integrity of the product applied to the stainless steel production Baosight one of them, the beginning of 2004 the entire production process to achieve and put into operation simultaneously. According to the China Information Industry Development Institute to do a report on the end of 2003, a total of 110 sets of MES applied to domestic steel companies. Co., Ltd. Deputy General Manager of Shanghai Bao Cong Liqun said the letter, the effective implementation of the MES building control systems can be achieved and management system seamlessly butt, this is not only a simple system to connect, network construction, more importantly, the docking information . Through this information the butt, making the whole decision-making in the steel business, management to control the process, the actual production data and production orders can be issued smoothly to upload and to realize the transmission of information is not ground.

Management of the 35 refineries of Sinopec MES technology is beginning to adopt scientific and effective management. China Petroleum & Chemical Corporation De-fang, director of information systems management, said, "Sinopec began in 2001 plans to build ERP, but we think not only ERP MES No, the information on the proposed 2004 meeting to increase MES system application building efforts. "In 2004, Sinopec has developed with independent intellectual property rights, in line with China's Sinopec petrochemical characteristics of MES system, called S-MESV1.0 version of the assessment by the 863 Group.

Under the guidance of the 863 Group, Sinopec began to pilot the implementation of the pilot phase, step by step marketing strategy. 2004, four enterprises MES system, despite the on-line for six months, MES systems initially show its advantages through the comprehensive tracking of logistics management, identify problems, can effectively reduce the loss of oil; the past, public works, water and power Wind management is weak, with this system on public works after the effective management of data, which reduces energy consumption and improve energy efficiency of resources; for the ERP system to provide accurate and timely ecological data, improve the effectiveness of ERP Application; across the enterprise management level of the fine has been increased.

Short space of time, MES system can quickly industrialization, De-fang said that "acceptance of the past, many projects are done mainly get away with winners. We MES project is taking the Combination of roads from the petrochemical PCG to take charge, using business models to form a unified intellectual property rights, the formation of unified design to ensure the integrity of the project and advanced. "

MES to promote energy saving

MES What are the advantages? Specialize in automation applications, according to market research firm ARC to make survey, if the application of MES, product quality can be improved 19.2%, close to 20%, labor productivity increased by 13%, yield 11%. 863 Modern Manufacturing Systems Technology Group Theme Group deputy head Chu Jian said, "even if the quality of products increased by 10%, 5% increase in labor productivity, reducing national energy consumption of raw materials is very great. Therefore, MES technology, if related industries in China, or energy, raw material consumption by the application of large, then China's energy economy, including environmental protection can be greatly improved. "

High energy consumption, which is the special circumstances facing our country, to save energy, we must optimize the technology. MES is the process industry, in the process industries, the need for the various departments have to become a corporate production indices production plan - Operational plan - operational standards - Process indicators - production order, and then processes the data acquisition system through and process control systems at various levels to return. By the operator to operate and control the production process, use this system to replace the functions of these departments. The concept of optimized integrated production targets is through the optimization process can produce a good indicator, then the behavior of the operator through the optimization of process indicators to produce the best settings. Such as extraction of gold if the standards set high, although the extraction of gold and high precision, but the efficiency is very low, cost increases, if the standard set of low grade gold would drop, so to set the best value, so that enterprises The cost is low, this is the optimal choice.

Implementation of the MES, the gold recovery rate increased by 2.1%, 0.57% grade increase, 50% attrition to reduce staff 237. There is also energy-saving and cost reduction. If a gold company investment in the whole system is about 5 million, according to this index to calculate the year and a half put 5 million fully recovered. "Just count the two indicators, grade and recovery rate of increase earn more productive gold mine," the Chinese Academy of Engineering, Tohoku University Professor CHAI said, "completely automated process industries may be in the advanced world level, China have this opportunity, China's industry immediately began to demand MES, only to contribute its technology and integrated with national objectives, optimization and intelligent expression, must be able to do a good job. "

MES into the national science and technology planning

"Ninth Five-Year" period, our country's manufacturing enterprises of the concept of MES is still relatively unfamiliar, "15" during the program 863 under the strong support, focusing on two typical steel and petrochemical process industries, Developed MES system of independent property rights, beyond the research stage at present MES basically have formed a number of industries, and has been successfully applied.

MES R & D has also produced a series of software technology and include the use of technology and process technology combining related technologies. Chu Jian, "15" are around during the MES major petrochemical, iron and steel industry started two major petrochemical industrial application of MES after the project application processing costs reduced by 1%, 1% operating efficiency. In the metallurgical industry, Bao letter in 2004, 2005, in Ningbo Baoxin, Jilin Tonghua Steel, the Shanghai Five steel companies to do the experiment, efficiency has been greatly improved. In addition, research and development around the MES has a range of relevant software, including advanced control and optimization, real-time database and monitoring platform, data correction and logistics tracking, data mining, monitoring and maintenance and so on-line software, these technologies are appropriate enterprises have a good application of the model. Chu Jian said, "the status of process industry in the country is important, long-term national energy plan released in such a set of data: in 2003 China's consumption of standard coal per 10,000 yuan GDP was 2.68 tons, expected to reach 2010 2.25 tons to 1.54 tons in 2020 hope to achieve. To achieve this goal, information technology, automation technology, including MES technology, can play a significant role. "

Chun Fung Kee High Science and Technology Division, said the national scientific and technological development in the formulation of long-term planning, scientists, entrepreneurs, economists, to strengthen our innovation and advanced manufacturing technology, conducted a systematic study, proposed including manufacturing information technology and green chemical process industry development strategies and recommendations, many elements have been incorporated into national development planning framework in the draft long-term.


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