外文翻译--可设计的逻辑控制器(编辑修改稿)

外文翻译--可设计的逻辑控制器(编辑修改稿)内容摘要：

ces logic and use saving machine electric circuit in of saving digital(procedure) replace after the cloth line of electric appliances system, rule a logic relation with the procedure。 Use the solid I/ O electric circuit to examine the signal of button and limit switch, carry out organization by the control electrical engineering and the other for an exportation. The PLC system that is at this time has already started have as follows some characteristics: The environment adaptability is stronger, can be use in a car the spot。 There is higher credibility and diagnosis ability, maintain easily。 Basic can adapt different manufacturing process need, the gentle degree more and greatly raised, want ～ only the procedure in the change system namely convertibility a control logic, but didn39。 t need to be reform or didn39。 t replace control hardware. Since 1976, the microprocessor starts lead into the PLC realm, consumedly strengthen a PLC function and make PLC from in brief replace after the electric appliances electric circuit, but develop to equip into the control which enters first. The PLC has to collect and handles a great deal of data, pletion mathematics operation and correspond by letter with other intelligence spare parts nowadays of ability, and have the forerunner39。 s person － machine to the words means(if keyboard, CRT and speech have a conversation), in recent years because of the spot emergence and related standard establishment of total line principle, and the quick development of product, the PLC bee the spot total line of an importance constitute part, extended PLC applied realm further. Because the PLC raised function with gentle degree in the meantime, make its application quickly increase, and make widely available many other longlost spare parts manufacture industry realm. Later on again expand to and criticize quantity to produce with continuous production line relevant of industrial realm. Along with the CIMS (calculator integration manufacturing system) development, the PLC is still used for factory by people to correspond by letter a work at present in, bee a calculator with other intelligence controllers and calculator system together prehensive control system in of importance constitute part, especially unit class and work station class. From 1969 the first set P L C publish up to now and the programmable controller about experienced three stages: First stage: The PLC capacity of the development is smaller, I/O the point be small at 120: customer saves area capacity or so scan the speed as 20~50 ms K B in the 2 KB s, the instruction is more simple and only have logic an operation and account, count etc., weave distance language to adopt a simple language sentence a predicative speech. Mainly use to make amount of switch a control on the usage. Second stage: The PLC capacity has to expand, the I/O point is from 5121024:00, customer39。 s procedure saves area to expand to 8 K B s above, the speed also has an exaltation, scan speed to attain a 5~6 ms K B, instruction function in addition to the basic logic operate, accounts, count, also increased an arithmetic operation instruction and pare instruction, and imitate a quantity processing instruction etc., input/output type also from pure switch quantity I/O, expand for the I/O which takes emulation quantity. Weave distance language in addition to using a language sentence form, can also use the trapezoid diagram plait distance。