外文翻译--plc控制系统设计的要点-plc设计(编辑修改稿)

外文翻译--plc控制系统设计的要点-plc设计(编辑修改稿)内容摘要：

alfunction is detected by the PLC logic. Advanced PLC systems also may have descriptions of the function of each circuit ponent. ⑦ Speed of Operation. Relays can take an unacceptable amount of time to actuate. The operational speed for the PLC program is very fast. The speed for the PLC logic operation is determined by scan time, which is a matter of milliseconds. ⑧ Ladder or Boolean Programming Method. The PLC programming can be acplished in the ladder mode by an electrician or technician. Alternatively, a PLC programmer who works in digital or Boolean control systems can also easily perform PLC programming. In modern industrial production equipment, and large numbers of simulations of the control devices, such as the cease electrical, electromagic devices to turn, the number of products, temperature, Ap power, and set the flow control, the automatic control of the industrial site, If a programmable controller (PLC) to resolve the issue has bee a cyberic one of the most effective tools, this article describes Plc control system design should be noted. Hardware purchase many products currently on the market Plc, with the exception of domestic brands, foreign : Japan Omron, Mitsubishi, FUJJ, ANASONIC, Germany Siemens, Korean LG. In recent years, Plc greater decline in the prices of products, increasing its performance cost rate. This is a technical staff chosen Plc important reasons. Then, how to purchase Plc products? First, the system should first determine the size of single control system with Plc or using Plc working, thus calculating Plc importing, exporting. Few, and in some Plc to be in real need have a certain cushion Second, determine the type of load under Plc exportled type of load is the DC or exchangetype, big or small currents, and Plc export points such as the frequency of movements, the use of relays to determine exportexport, or transistor output, or goods of export gates. Different load choose different ways to export to the operating system39。 s stability is very important. Third, the storage capacity and speed while foreign manufacturers of Plc products essentially the same, but there are some differences. Currently the pany has not yet found full patibility between products. The development of software panies are not the same, and users of storage capacity and procedures to implement the Directive speed are two important indicators. General greater storage capacity, faster speed on the Plc higher prices, but should be based on system size reasonable choice Plc products. Fourth, programming devices Plc programming can purchase three ways : Using handheld programming device programming in general, it can provide businesses phrases programming language table. This approach inefficient, but the capacity of small systems, the products more suitable for small consumption, and small size, ease of debugging scene, but also lower costs. Using graphical programming device programming, the programming device used Trapezoid Chart programming for visual and general electrical personnel shortly be applied easily, but the programming device prices higher. Using IBM personal puters and software packages using Plc programming, this approach is the most efficient way, but most of the pany39。 s Plc development software packages expensive, and that means not at the scene。