【溫馨提示】 dwg后綴的文件為CAD圖，可編輯，無水印，高清圖，，壓縮包內(nèi)文檔可直接點開預覽，需要原稿請自助充值下載，請見壓縮包內(nèi)的文件及預覽，所見才能所得，請細心查看有疑問可以咨詢QQ：414951605或1304139763
外文翻譯資料
Downloading more PAC technical paper and
video frequency course
Has produced along with many merchants can unify the PC function and the PLC reliable programmable automation controller (PAC), at present the control system gradually started to use PAC. This white paper introduced PAC the origin as well as it with PLC and the PC difference, and had pointed out will use PAC the industry to control the future development direction.
Table of contents
PAC will become the future the industry control mode
"80-20" principle
Constructs a better controller
Two kind of different softwares solution
PAC vision and survey application
PAC has avoided to the special hardware need
LabVIEW uses in the automated control
NI PAC system
PAC will become the future the industry control mode with compares based on the PC control system, related PLC (programmable logical controller) the superiority and the inferiority intense argument has already continued for ten years. Because PC and PLC are more and more small in the technical difference, and has used the commercialization along with PLC (COTS) the hardware as well as PC can use the real-time operating system, thus appeared one kind of new form controller - PAC. The PAC concept is (ARC) proposes by the automation development facility, it expressed the programmable automated controller, used in describing unified PLC and the PC function new generation of industry controller. The traditional PLC merchant uses PAC the concept to describe their high end system, but PC control merchant then uses for to describe their industrialization to control the platform.
"80-20" principle
In PLC in 30 years which developed, it passes through develops unceasingly, already could unify simulates I/O, the network corresponds as well as uses new programming standard like IEC 61131-3. However, engineers only must use digital I/O and few simulations I/O number as well as simple programming skill on potential 80% industrial application. Comes from ARC, the unit exploitation company (VDC) as well as on the net PLC training resources PLC. The net expert estimated that,
77% PLC uses in the small application (being lower than 128 I/O)
72% PLC I/O is a numeral
80% PLC application may use 20 trapezoidal logical sets of instructions to solve
Because uses traditional the tool to be possible to solve 80% industrial application, like this intensely needs to have low cost simple PLC; Thus promoted the low cost miniature PLC growth, it has the useful trapezoidal logical programming digital I/O. However, this has also created the discontinuity in the control technology, on the one hand 80% application need to use the simple low cost controller, but on the other hand other 20% application then have surpassed the function which the tradition control system can provide. Engineer is developing these 20% application to need to have the higher circulation speed, the senior control algorithm, the more simulations function as well as can well and the enterprise network integration.
In 80 and the 90's, these must develop "20% application" engineers had considered uses PC in the industry control. PC provides the software function may carry out the senior task, provides the rich programming and the user environment, and the PC COTS part enables control engineer the technology which develops unceasingly to use in other applications. These technologies including floating point processor; High speed I/O main line, like PCI and ethernet; Fixed data memory; software development kit. Moreover PC also can provide the incomparable flexibility, highly effective software as well as senior low cost hardware.
However, PC is not extremely suitablly uses in controlling the application. Although many engineers in integrated senior function time uses PC, these functions including simulation control and simulation, connection database, network function nf as well as with third party equipment correspondence, but PLC still was at the dominant position in the control domain. Is standard PC is not but designs based on the PC control main question for the strict industry environment.
PC mainly faces three major problems:
Stability: The usual PC general operating system cannot provide uses in controlling the enough stability. The installment can force the processing system collapse based on the PC control equipment and not expect to again opens.
Reliability: Because PC has the magnetic hard disk and the non- reliable part which revolves, like the power source, this makes it to be easier to appear the breakdown.
Not familiar programming environment: The factory operator needs to have when maintains and fixes the breakdown restores the system the ability. The use trapezoidal logic, they may manual force the coil to restore to the perfect condition, and can fast patch the code which affects by is fast restored the system. However, the PC system needs the operator to study the new higher paraffin the tool.
Although certain engineers use have the firm hardware and the specially operating system special-purpose industry computer, but because Engineer PC reliable aspect question overwhelming majority avoids in the control using PC. In addition, uses in each kind of automated duty equipment in PC, like I/O, correspondence, or movement possible need different development environment.
Therefore these must develop "20% application" engineers either use PLC to be unable with ease to realize the function which the system needs, either uses both contains PLC and to contain PC the mix system, they use PLC to carry out the code control section, realizes the higher paraffin function with PC. Thus the present many factories workshops use the system which PLC and PC unifies, in use system PC carries on the data record, the connection bar code scanner, inserts the information in the database as well as issues the data to the net on. Uses this way establishment system the main question is this system with difficulty constructs frequently, fixes the breakdown and the maintenance. System engineer must unify frequently comes from many merchants software and hardware work to puzzle, this is because these equipment are not but design for can the joint operation.
Constructs a better controller
Because does not have suitable PC or the PLC solution, these need development complex application engineer on develops the new product with the control merchant close cooperation. They need the new product to be able to unify PC the senior software function and the PLC reliability. These important users were PLC and have provided the product development instruction based on the PC control company.
Realizes the software function not only to need to have the senior the software, moreover the controller hardware function also needs to have the enhancement. Because in the world scope is dropping to the PC part demand, therefore many semiconductors merchants start for the industrial application redesign their product. At present controls the domain the merchant to start in the industry control product to use the industrialization floating point processor, DRAM, solid state memory like Compact Flash as well as the fast Ethernet chip. This enables the merchant to use based on the PC control system flexibility and the usability develops a more formidable software, moreover this PC control system also may move the real-time operating system by to guarantee the reliability.
This kind of new controller is the solution "20%" the application question but designs, it unified PLC and the PC two merits. The ARC industry analyst is called this kind of equipment the programmable automated controller, namely PAC. "The programmable logical controller world looks at in generally" the research in ARC, they have produced the PAC five principal characteristics. These controller characteristics are through define the software the ability to realize its function.
"Multi-purpose, has in the logic, the movement, the PID control, the actuation and processing in a platform at least two kind of above functions." Except that in order to realize special agreement like SERCOS to have to I/O makes some improvements; Moreover the software also can provide logical, the movement, processing and the PID function. For example, the movement control took the software control circulation, it can reading the digital input from the orthogonal encoder, the execution simulation control circulates and outputs the control device the simulated signal.
"The sole multi- regulations develop the platform use general label and the sole database visit all parameters and the function." Because PAC is like multi-purpose but designs for more the senior application, they need the senior software. In order to can highly effective design the system, the software must be the sole integrated software package, but is not the many kinds of separations software tool, these software tools in the project cannot the seamless joint operation.
"Through unifies IEC61131-3, the user guide and the data management, the software tool can design is surmounting many machines and the processing unit processing flow." The simplification system design on the other hand is has the senior the development kit, uses this tool to be possible to cause engineer very with ease to transform the processing concept for can actual control the machine the code.
"The opening modular skeleton can solve the industrial application may distribute from the control in the factory machine to processes workshop the operation unit." Because all industrial application all needs to have highly has custom-made the characteristic, therefore the hardware must be the modulation in order to engineers may choose the appropriate part. Moreover, the software also must be able to let engineer increase and the demolition module by the system which designs needs.
"Uses already the network interface standard which has, the language and so on, like TCPIP, OPC&XML and SQL inquiry language." Can with enterprise's network correspondence regarding the modernization control system be extremely essential. Although PAC contains has the ethernet connection, but in order to must does not have the equipment and the factory other systems the question to integrate in together, corresponds the software is very important.
Two kind of different softwares solution
On the one hand the software is PAC and the PLC main difference, but on the other hand the merchant in provides the senior software in the way also to differ from. Usually they the control software which has have taken the beginning by at present, increases the function, the reliability and the usability unceasingly which the PAC programming needs. In general, some two kinds provide the PAC software the way: Based on PLC control software and based on PC control software
Based on PLC concept software plan
The traditional PLC software merchant take is reliable also Yi Yong scanning type overhead construction software as a beginning, and increases the new function gradually. The PLC software basis general model but establishes: The input scanning, the control code movement, the input renews, as well as conventional function execution. As a result of the input circulation, the output circulation and the conventional circulation all is the hideaway, therefore control engineer only must pay attention to the control code the design. Because the merchant has completed the majority of work, this kind of strict control overhead construction causes the establishment control system to be easier and to be fast. These systems strict also can let control engineer when the development reliable procedure does not need thoroughly to understand PLC the first floor operation. However, also causes its flexible as the PLC main superiority this kind of strict scanning type skeleton being short of. The overwhelming majority PLC merchant through in the scanning type overhead construction which has increased the new function to establish the PAC software, these new functions including ethernet correspondence, movement control and senior algorithm. However, usually they can retain the PLC familiar programming way as well as it in logical and the control aspect inherent characteristic. Therefore this kind of PAC software usually is for suit the special type application but to design, like logic, movement and PID, but regarding the application which has custom-made then lacks the flexibility, like the correspondence, the data record or have custom-made control algorithm.
Based on PC concept software plan
The traditional PC software merchant take the extremely nimble general programming language as a beginning, can provide to the hardware deep level visit. This kind of software also has the control overhead construction which the reliability, determinism as well as supposes in advance. Although engineer can be the PLC programmers establishes the scanning type skeleton, but it is not based on the PC software inherent. These cause the PC software to be extremely nimble, suits these need senior extremely the overhead construction, the programming skill or the control complex application, but causes originally to be supposed actually the simple application complication.
These merchants first must be able to provide the reliability and determinism which general operating system like Windows does not have. They may through use the real-time operating system (RTOS) Tathagata realize from Ardence Phar Lap or Wind River VxWorks. These RTOS can control system each stratification plane, from I/O read-write speed to controller on each regulation priority. Then in order to enable engineer easily to develop the reliable control procedure, the merchant increased the abstract level and I/O read-write overhead construction. Thus this kind of nimble software suits extremely in the customized control, data record and correspondence, but discards the PLC programming overhead construction the price is causes the procedure the development difficulty increase.
NI has developed can move LabVIEW procedure a series of PAC to deliver the platform. LabVIEW has become tests and surveys the software the fact standard. It has direct-viewing being similar in the flow chart programming way, and through is easy the contact surface which uses to provide all functions which the senior programming language has. Using LabVIEW RT and LabVIEW FPGA, we can unify LabVIEW and the real-time operating system and download directly to FPGA (scene programmable gate array) the platform provide the reliability and determinism.
Based on PAC vision and survey application
NI has the survey the profession background, it caused PAC through the introduction high speed survey and the machine vision to surmount simple I/O. Needs high speed to gather the measurement result in many industrial applications by to use in vibrating or the power quality analysis. Gathers to the data uses for to monitor revolves the machinery condition, determined the maintenance timetable, distinguishes the electrical machinery the attrition degree as well as the adjustment control algorithm. Engineers the usual use special data acquisition system or the independent instrument gather these data and the use correspondence main line the data feeds to the control system. But NI PAC may carry on the high accuracy directly by each second million speed the survey, and transmits directly the data to the control system processes immediately.
Engineers also may use the visual function in theirs control system. In the past in ten years the vision obtained in the automated domain swiftly and violently has developed. In the production environment, some many products flaw or the wrong use tradition measuring technique is very difficult to distinguish, but through visual way then can examine. The common application including uses in producing or the assembly examination components examination, like on test circuit board component position is whether correct, the recognition optics character (OCR) inspects the date bar code or carries on the classification to the product, as well as carries on the optical measurement to discover the product the slight defect or carries on the classification to the product according to the quality rank. At present many factories use independent intelligent, it must carry on the correspondence with the production processing controller. The NI PAC introduction has logical and the movement control vision perhaps the high speed survey function, thus causes engineers not to need to integrate other hardware and the software platform.
PAC has avoided regarding the special hardware need
PAC is representing the programmable controller newest technology, it future will develop the key will be decided in inserts the type technology the introduction. For instance must be able to define the hardware through the software. The electronic merchant often uses the chip which the scene programmable gate array (FPGA) such electronic device develops has custom-made, it may let the new equipment intellectualization. These equipment contain have can carry out the many kinds of functions to be possible to dispose the logical block, connects these function blocks programmable junction association as well as for chip input output data I/O. Through defines these to be possible to dispose the logical block the function, its each other connection as well as corresponding I/O, the electron designs the chip which the personnel namely may develop has custom-made, but does not need to spend produces special ASIC. FPGA is similar to has a computer, its internal circuit can reconnect moves the specific application procedure.
Before only then these familiar first floors programming language like VHDL hardware designs the personnel to be able to use the FPGA technology. However, engineers have now been possible to use the control algorithm which LabVIEW FPGA develops has custom-made and it to download to the FPGA chip on. May cause the hardware through this characteristic engineers to have the real-time function, like the limit and approaches the sensor examination and the sensor condition monitoring. Because the control code moves directly on the chip, therefore engineers can fast develop the correspondence agreement or the high speed circulation procedure which uses has custom-made: The numerical control circulating rate may reach as high as 1 MHz, the simulation control circulation speed may be 200kHz.
LabVIEW uses in the automated control
As a result of LabVIEW (ni.Com/China/Labview) has the formidable function and the programming usability, extremely suitablly has the following request based on LabVIEW PAC the application:
Because LabVIEW programs the inborn introduction graphical user interface, you may provide the man-machine contact surface for the control system.
Survey (high speed data gathering, vision and movement). NI is including visual gathering high speed I/The O aspect has the long-term experience, therefore you may use function and so on vibration or machine vision in yours standard control system.
Handling ability: In certain applications, you need to have the special control algorithm, the senior signal processing or the data record. Uses LabVIEW, you may use the control code which NI or the third party tool establishes has custom-made, the realization like JTFA signal processing, or local and long-distance data recording.
Platform: Using LabVIEW, you can develop use in each kind of platform code, these platforms include PC, inserts the type controller, the FPGA chip or handhold PDA.
Correspondence: Using the LabVIEW database connection, OPC and based on the network browser operation contact surface, you can very easily the data transfer to the enterprise database in.
The system of N