【正文】 r operations into and out of storage exists in the procedures of PLC. PLC procedures established manufacturers of the system procedures (irrevocable), and users develop their own applications (users) procedures. Operating system platforms provide procedures, and procedures for the PLC signal and reliable operation of the public with the information necessary conversion. Users control procedures designed by the users. What kind of control, due to what the user procedures. Reliable physical realization mainly relies on anyone else (input) and (output) circuit. PLC’s I/O circuits are specially designed. Of a filter circuit to input signal to eliminate highfrequency interference. But with the internal puter circuits, electricity is isolated and it also relies on photocoupling working ponents. Guangou ponents export relays working exports from electricity within and outside the circuit, or. A power output circuit also enlarged to be sufficient to general industrial control ponents, such as electromagic valves, contact devices, and so on. For example: I/O circuits contains a lot of sorts, each entry points or export points to a circuit I or O. PLC with how I/O point, the general will use a number of I/O circuit. But because the highly integrated circuit provided them, so size is not large share. Constantly monitored the importation of circuit status and pending in the importation of Shortterm storing equipment. Each entry point has a corresponding memory of their information Shortterm storing equipment Export circuit to export fliplatch devices messaging to export points. Export fliplatch and the output is also gathers Import and export of fliplatch and Shortterm storing equipment here are the actual device of PLC processors I/O the register. They exchange information through puters and puter memory bus, and primarily by the realization of operating system procedures. Shortterm storing equipment is to lose people read the information within the PLC, it is said that the importation of regeneration. PLC is within the open storage of specialized information shine upon area. Each of the district counterpart spaces (bit) as input relays, or those soft contacts. These positions into one that includes links, home to multiple broken into 0. Because it is the state of renewable received, so that it is reflected in the imported state. Export fliplatch and the PLC memory areas are exported shine upon counterpart. 1export fliplatch have a hard place (bit) with its counterpart, the place known as export relays, or that exporting coil. By operating system procedures, and the output relays shine upon the state to export fliplatch. Also known as the shine upon exporting renewable. Is the main operating system on renewable export procedures achieved? Thus, users only need to be procedures that exist in the area of shine upon export shine upon their zone, especially in the importation of the time series is converted into the output time series. This is a logic and data processing. The PLC is a powerful mand system, the procedures to prepare to meet this requirement is entirely possible, but also relatively easy. 4 Programmable Controller Achieve Control Of The Process Briefly, PLC controlling process is usually achieved: Of renewable to users operating procedures to export renewable further importation of renewable to users operating procedures to export renewable: never stop to the cycle of repeated carried out. With the abovementioned process, the realization of a PLC control is clearly possible. Because: With the importation of renewable, can be imported by the import control circuit input shine upon information deposited PLC District。 By users operating procedures, and the output will be used after the district shine upo n information。 After exporting renewable exporting fliplatch will be reflected shine upon export zone status, and a corresponding export through export circuit. Also as a result of this process is never ceasing to cycle repeatedly carried out, it is always reflect input from the changes. Response time is only slightly behind. Of course, this should not lag too much, otherwise achieved control less timely lose control of significance To this end, the PLC work faster. Speed, execution time is short, the realization is PLC controlled. In fact, it is the speed soon, the implementation of a directive, several more elsewhere, scores elsewhere, but only of the few, or few refinements. And the speed is constantly improving. In addition to operational users I/O renewable and procedures, but also do public address work Report processing: cycle time monitoring, and engineered services and munications processing. Control cycle time in order to avoid dead cycle in order to avoid duplication of procedures cannot be repeated continuously. Approach is the use of man (Watching dog). As long as the cycle of overtime, it can report or consequential. The external services is acceptable for PLC programming by its operation, or through interfaces to export equipment, such as printers output data Communications processing is a PLC or puter, or other industrial control devices or the exchange of information among intelligence ponents. This is also enhanced PLC control needs In other words, the actual process always PLC: public address I/O renewable users operating procedures to the public address : repeated constantly. Programmable Controller Means To Achieve Control This constant repetition of the operation procedures is used to achieve that control scanning. Is a puterbased realtime control? In addition, there are puters for control interruption. Interruption in the form of applications to be processed first interruption control, the procedure was to stop the operation after the operation is