PLC的控制优势 毕业论文外文翻译.doc

唐 山 学 院 毕 业 设 计外文资料plc control advantage any control system from concept to enter factory work have to undergo four stages. plc system in each stage has advantage. the first stage is designed to plant needs, study and formulate control strategy, the traditional operating platform design and manufacture must be finished before in design. plc system just need is a vague about the size of the machine may idea and i/o number of requirements (much input and output interface). in this phase input and output chip very cheap, so can a built-in very sound reserve capacity, it allows used to supplement omission for future expansion project and prepare it. secondly, the traditional design scheme is, every job is a once moldings the inevitable caused engineering delays and increase costs. a plc systems use the simplest standard bolt together. in such a connection next began writing plc program (or at least the program codes) write detailed. the next stage is to install, installation is a kind of complicated and expensive work, such as the install sensors, actuators, limit switch system and the host of connection. distributed plc systems use serial links type pre-compiled, testing interface can be simplified install it have come at a huge cost advantage. plc program most in this stage finish. finally commissioning, and this is what is the advantage of plc real were excavated part. without any equipment in the first would work normally. such is human nature, theres some omissions. and the traditional system changes, compared the time-consuming and expensive plc designer provided system built-in backup memory reserves, spare i/o and some spare much core cable, most of the changes to can be quickly and relatively cheap completed, another benefit is that all changes plc has records, program degugging and modify wont because unrecorded lost. this is a regular system often happens in the problem. there is an additional fifth stage, maintenance, once started work, and hand over the production has produced maintenance. all equipment all have weaknesses, most equipment in the wrong mode spent much of their time. plc system provides a very powerful tool to help diagnose failure.plc的控制优势任何控制系统从概念到进入工厂工作都要经历四个阶段。plc系统在每一个阶段都有优势。第一个阶段是设计，对工厂的需要进行研究和制定控制策略，传统的运行平台的设计和制造必须在设计进行前完成。plc系统仅仅需要的是一个模糊的关于机器的可能大小的想法和i/o数量的要求（多少输入和输出接口）。在这个阶段输入和输出芯片十分便宜，所以可以内置一个很健全的备用容量，它允许用来补充遗漏项目和为未来的扩充做准备。其次是设计，传统的方案是，每一项工作都是“一次成型”这不可避免的造成了工程拖延和增加成本。一个的plc系统使用最简单的标准件螺栓连接在一起。在这样的连接下开始编写plc程序（或者至少是写入详细的程序规范）。下一阶段是安装，安装是一种繁琐和昂贵的工作，例如安装传感器、执行器、限制开关系统和主机的连接。分布式plc系统使用串行链路式的预编译，测试界面可以简化安装它带来了巨大的成本优势。plc的程序多数在这个阶段完成。最后是调试，而这正是plc真正的优势被发掘的部分。没有任何设备在第一次就正常工作。人性就是这样，总会有一些疏漏。与传统的系统变动情况的耗时和昂贵相比，plc的设计师提供了系统的内置备用内存储量、备用i/o和一些备用多芯电缆向，多数的变动能迅速和相对便宜的完成，另一个好处是，所有的