【導(dǎo)讀】自從全自動洗衣機(jī)誕生以來，其內(nèi)部的電路控制系統(tǒng)就不斷的被改進(jìn)。法也開始多種多樣，從而使全自動洗衣機(jī)顯得更加智能化。氣原理圖編制的梯形圖語言進(jìn)行程序設(shè)計(jì)，編程容易，功能擴(kuò)展方便，修改靈活,而且結(jié)構(gòu)簡單，抗干擾能力強(qiáng)。西門子S7-200系列可編程控制器指令豐富，可以。信設(shè)備更是符合全自動洗衣機(jī)控制系統(tǒng)的要求與特點(diǎn)。語句表進(jìn)行編程，實(shí)現(xiàn)了全自動洗衣機(jī)控制系統(tǒng)的自動化。

　　

【正文】 ctually is that part of a puter, PLC, or other intelligent device where arithmetic and logical operations are performed and instructions are decoded and executed. Daisy chain: This is a description of the connection of individual devices in a PLC work, where, as shown in Fig. 3, each device is connected to the next and munications signals pass from one unit to the next in a sequential fashion. Distributed control: This is an automation concept in which portions of an automated system are controlled by separate controllers, which are located in close proximity to their area of direct control (control is decentralized and spread out over the system). Host puter: This is a puter that39。s used to transfer data to, or receive data from, a PLC in a PLC/puter work. Intelligent device: This term describes any device equipped with its own CPU. I/O: This stands for inputs and outputs, which are modules that handle data to the PLC (inputs) or signals from the PLC (outputs) to an external device. Kbps: This stands for thousand bits per second, which is a rate of measure for electronic data transfer. Mbps: This stands for million bits per second. Node: This term is applied to any one of the positions or stations in a work. Each node incorporates a device that can municate with all other devices on the work. Protocol: The definition of how data is arranged and coded for transmission on a work. Ring topology. This is a LAN arrangement, as shown in Fig. 2C, in which each node is connected to two other nodes, resulting in a continuous, closed, circular path or loop for messages to circulate, usually in one direction. Some ring topologies have a special loop back feature that allows them to continue functioning even if the main cable is severed. 洛陽理工學(xué)院 畢業(yè)設(shè)計(jì) 31 RS232. This is an IEEE standard for serial munications that describes specific wiring connections, voltage levels, and other operating parameters for electronic data munications. There also are several other RS standards defined. Serial: This is an electronic data transfer scheme in which information is transmitted one bit at a time. Serial port: This the munications access point on a device that is set up for serial munications. Star topology. This is a LAN arrangement in which, as shown in Fig. 2B, nodes are connected to one another through a central hub, which can be active or passive. An active hub performs work duties such as message routing and maintenance. A passive central hub simply passes the message along to all the nodes connected to it. Topology: This relates to a specific arrangement of nodes in a LAN in relation to one another. Transparent: This term describes automatic events or processes built into a system that require no special programming or prompting from an operator. Now that we39。re familiar with these terms, let39。s see how they are used in describing the available PLC work options. PLC work options PLC works provide you with a variety of working options to meet specific control and munications requirements. Typical options include remote I/O, peertopeer, and host puter munications, as well as LANs. These works can provide reliable and costeffective munications between as few as two or as many as several hundred PLCs, puters, and other intelligent devices. Many PLC vendors offer proprietary working systems that are unique and will not municate with another make of PLC. This is because of the different munications protocols, mand sequences, errorchecking schemes, and munications media used by each manufacturer. However, it is possible to make different PLCs talk to one another。 what39。s required is an ASCII interface for the connection(s), along with considerable work with software. 洛陽理工學(xué)院 畢業(yè)設(shè)計(jì) 32 Remote I/0 systems A remote I/O configuration, as shown in Fig. 4A, has the actual inputs and outputs at some distance from the controller and CPU. This type of system, which can be described as a masterandslave configuration, allows many distant digital and analog points to be controlled by a single PLC. Typically, remote I/Os are connected to the CPU via twisted pair or fiber optic cables. Remote I/O configurations can be extremely costeffective control solutions where only a few I/O points are needed in widely separated areas. In this situation, it39。s not always necessary, or practical for that matter, to have a controller at each site. Nor is it practical to individually hard wire each I/O point over long distances back to the CPU. For example, remote I/O systems can be used in acquiring data from remote plant or facility locations. Information such as cycle times, counts, duration or events, etc. then can be sent back to the PLC for maintenance and management reporting. In a remote I/O configuration, the master controller polls the slaved I/O for its current I/O status. The remote I/O system responds, and the master PLC then signals the remote I/O to change the state of outputs as dictated by the control program in the PLC39。s memory. This entire cycle occurs hundreds of times per second. Peertopeer works Peertopeer works, as shown in Fig. 4B, enhance reliability by decentralizing the control functions without sacrificing coordinated control. In this type of work, numerous PLCs are connected to one another in a daisychain fashion, and a mon memory table is duplicated in the memory of each. In this way, when any PLC writes data to this memory area, the information is automatically transferred to all other PLCs in the work. They then can use this information in their own operating programs. With peertopeer works, each PLC in the work is responsible for its own control site and only needs to be programmed for its own area of responsibility. This aspect of the work significantly reduces programming and debugging plexity。 because all municat