【正文】 ign stage, single functions are designed and verified. At system design stage, ponents are aggregated and the whole system behavior and functionality is tested through simulation. In general, a plete verification is impossible. Hence, a systematic approach as exemplified for the PLC program design may impact the logical hardware design. SIEMENS PLC SIMATIC S7300 series PLC applied to all walks of life and various occasions in the detection, monitoring and control of automation, its power to both the independent operation of, or connected to a network able to achieve plex control. The photoelectric products with isolation, high electromagnetic patibility。 have high industrial applicability, allowing the ambient temperature of 60 ℃。 has strong antijamming and antivibration and impact resistance, so in a harsh working environment has been widely Applications. I also mean freedom of munication S7300 type PLC39。 s a very unique feature, which allows S7300PLC can deal openly with any other munications equipment, munications controller, or PLC S7300 type can be defined by the user39。s own Communications protocol (of the agreement ASCII), the baud rate to M bit / s (adjustable). So that can greatly increase the scope of munications so that the control system configuration more flexible and convenient. Of any kind with a serial interface peripherals, such as: printers or bar code readers, Drives, a modem (Modem), the top PCconnected, and so can be used. Users can program to develop munication protocols, the exchange of data (for example: ASCII character code), RS232 interfaces with the equipment can also be used PC / PPI cable linking the free munication munications. When the PC offline, under the control of the next crew, the whole system can operate normally. PC that is by control centre, mainly by the PC and laser printer ponents, using SIMATIC WINCC software platform, the allChinese interface, friendly manmachine dialogue. Managers and operators can be observed through a PC, shown in the various kinds of information to understand the present and past the icestorage operation of the automatic control system and all the parameters, and through the mouse to print equipment management and implementation tasks. WINCC software in the field of automation can be used for all the operators’ control and monitoring tasks. Can be controlled in the process of the events clearly show, and shows the current status and order records, the recorded data can show all or select summary form, or may be required for editing, printing and output statements and trends . WINCC able to control the critical situation in the early stages of the report, and the signal can be displayed on the screen, can also use sound to be felt. It supported by online help and operational guidelines to eliminate failure. WINCC a workstation can be devoted to the process control to the process so that important information not is shielded. Softwareassisted operation strategy ensures that the process was not illegal to visit and to provide for nonindustrial environment in the wrong operation. WINCC is MICRSOFT WINDOWS98 or WINDOWS operating system, running on a PC objectoriented class 32bit application, OLE through the window and ODBC standard mechanism, as an ideal partner to enter the munications world WINDOWS, it can be easily WINCC To integrate a panywide data processing system. Communications Communications are vital to an individual automation cell and to the automated factory as a whole. We39。ve heard a lot about MAP in the last few years, and a lot of panies have jumped on the band wagon. Many, however were disappointed when a fullydefined and pleted MAP specification didn’t appear immediately. Says Larry Kumara:” Right now, MAP is still a moving target for the manufacturers specification that is not final. Presently, for example, people are introducing products to meet the MAP products will be obsolete when the new standard for MAP, introduced.” Because of this, many PLC vendors are holding off on full MAP implementations. Omron, for example, has an ongoing MAPpatibility program, but Frank Newborn, vice president of Omron’s Industrial Division, reports that because of the lack of a firm definition, Omron39。s PLCs don39。t yet talk to MAP. Since it’s unlikely that an individual PLC would talk to broadband MAP anyway, makers are concentrating n proprietary networks. According to Sal Provanzano, users fear that if they do get on board and vendors withdraw from MAP, they all pulse width modulation control system be the ones left holding a munications structure that’s not supported.34