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1、毕业实践任务书课题名称 PLC控制的变频电梯系统的设计 指导教师 职 称 专业名称 班 级 学 生 姓 名 学 号 课题需要完成的任务：电梯控制的基本思路是当电梯上升下降时，在上升下降的同时，要顾及到等待时间、加速时间，人性化的设计。在上升时，有人按了上升按钮，则要在经过的时候停止，开门；下降时亦相同。系统主要由变频器，PLC，曳引电机，按钮四部分组成。按钮连接PLC的I/O口，按下按钮的时候，PLC将信号转换为模拟信号，传给变频器，变频器改变曳引电机的转向。其中曳引电机的速度改变。主要完成任务如下：（1） 三菱公司的FX2N-80MR-D模拟量扩展模块的程序设计（2） 变频器控制的程序设计课
2、题计划：x.xx.x 熟悉课题，准备资料； x.xx.x 设计硬件； x.xx.x 编写毕业设计论文； x.xx.x 准备毕业答辩。计划答辩时间：xxxx年x月x日x日 xxxxxx（分院、系部）xxxx年xx 月xx日外文翻译INDUSTRIAL AND COLLABORATIVE CONTROL SYSTEMS- A COMPLEMENTARY SYMBIOSIS Looking at todays control system one can find a wide variety of implementations. From pure industrial to collabora
3、tive control system (CCS) tool kits to home grown systems and any variation in-between. Decisions on the type of implementation should be driven by technical arguments Reality shows that financial and sociological reasons form the complete picture. Any decision has its advantages and its drawbacks.
4、Reliability, good documentation and support are arguments for industrial controls. Financial arguments drive decisions towards collaborative tools. Keeping the hands on the source code and being able to solve problems on your own and faster than industry are the argument for home grown solutions or
5、open source solutions. The experience of many years of operations shows that which solution is the primary one does not matter, there are always areas where at least part of the other implementations exist. As a result heterogeneous systems have to be maintained. The support for different protocols
6、is essential. This paper describes our experience with industrial control systems, PLC controlled turn key systems, the CCS tool kit EPICS and the operability between all of them.FUNCTIONALITY The ever lasting question why control systems for accelerators and other highly specialized equipment are o
7、ften home grown or at least developed in a collaboration but only in rare cases commercial shall not be answered here. We try to summarize here basic functionalities of different controls approaches.Front-end Controller One of the core elements of a control system is the front-end controller. PLCs c
8、an be used to implement most of the functions to control the equipment. The disadvantage is the complicated access to the controls properties. For instance all of the properties of a control loop like the P, I and D parameter, but also the alarm limits and other additional properties must be address
9、ed individually in order to identify them in the communication protocol and last not least in the display-, alarm- and archive programs. In addition any kind of modifications of these embedded properties is difficult to track because two or more systems are involved. This might be one strong argumen
10、t why control loops are mainly implemented on the IOC level rather than PLCs. I/O and Control Loops Complex control algorithms and control loops are the domain of DCS alike control systems. The support for sets of predefined display and controls properties is essential. If not already available (lik
11、e in DCS systems) such sets of generic properties are typically specified throughout a complete control system (see namespaces). Sequence/ State programs Sequence programs can run on any processor in a control system. The runtime environment depends on the relevance of the code for the control syste
12、m. Programs fulfilling watchdog functions have to run on the front-end processor directly. Sequence programs for complicated startup and shutdown procedures could be run on a workstation as well. The basic functionality of a state machine can be even implemented in IEC 61131. Code generators can pro
13、duce C code which can be compiled for the runtime environment. Supported Hardware The support for field buses and Ethernet based I/O is a basic functionality for SCADA type systems it is commercially available from any SCADA system on the market. The integration of specific hardware with specific dr
14、ivers and data conversion is the hard part in a commercial environment. Open APIs or scripting support sometimes help to integrate custom hardware. If these tools are not provided for the control system it is difficult if not impossible - to integrate custom hardware. New industrial standards like O
15、PC allow the communication with OPC aware devices and the communication between control systems. One boundary condition for this kind of functionality is the underlying operating system. In the case of OPC it is bound to DCOM which is a Microsoft standard. UNIX based control systems have a hard time to get connected. Only control systems supporting multiple platforms can play a major role in a heterogeneous environments. As a result the limited support for custom- or specialized hardware may give reason for the development
