ABSTRACT
This design is main in use PLC to achieve the system’process automation which name is the process conditions of intelligence stocks fix a position choose take or get goods. this design is to bring out interlock from equipage to equipage and bring out the whole system of the work of mechanism in the system’demand. the design is relate to control-program of fix a position control system in PLC. choose tape of equipment of PLC and software design of the system.
There are 4 part in the flow path of the whole system which name is the process of machine go forward, the process of machine to lift , the process of machine retreat,the process of machine go back. on the basis of the conditions flow path and condition of fix a position control system of the equipage, PLC control -program is the main control programme in the system. PLC control-program’s advantage is it which in good dependable and in good resistance,it can apply flexibleiy. PLC control-program is easy to make program and in good function.its expandance is very good.it is easy to install and text.it can keep in good repair.so it is a good control-program.
The first step of the whole design system is to know the system’ demand of grain allocate and transport, on the basis of system’demand it is time to draw the port of detection and start to design the PLC control-program system.the second step is to choose the right CPU.because the system has 45 I/O port .in the part, I thought of every thing about the grain allocate and transport system, so I choose CPU224 of siemens s7-200 .it possess 256 I/O port.CPU224 has good capactity of communication and it can keep in good touch with up-bit machine on net .software design is use the way of the form of models in section, it is bring out the system’demand very well. it can make the program clearly. it is easy to make people study and keep in good repair.
KEY WORDS:plc, position control system, intelligence stocks