PLC Based On ARM With FPGA And Its Ladder Diagram Programming System

Programmable logic controller(PLC) is widely used in industrial control field, which occupies the biggest share of the market of motion controller. It can be programed by ladder programming language, which make it much easier to design motion control system. Comparing to other motion controllers, it has great disvantages in motion control performance and real time performance.This paper combines the advantages of PLC and other kinds of motion controlles, designs a PLC with good motion control performance and good real time performance based on the architecture of ARM andFPGA. In order to make it easier to program, we design ladder diagram programming system of PLC proposed in this paper. The main work done is as follows:(1) PLC hardware system is designed using ARM and FPGA architecture that has good real time performance to assume the hardware system have good real time performence. And overall scheme of the PLC software system is designed based on the architecture. According to the demand of the ladder diagram programming system of PLC, the framework of the programming system is designed, which contains edit module, compile module, download module and simulation module.(2) This paper designs and implements the functions of analytical target code cyclely, download and communication, save electricity data, and motion control in the ARM side of the PLC software systems based on μC/OS-Ⅱwhich has good real time performance.(3) This paper designs the data structure of ladder diagram component and layering saving mode of it. According to the data structure and the saving mode, this paper designs and realizes the interface design submodule, edit function management submodule, display submodule, saving and loading submodule of the edit module.(4) This paper divides the procedure of compile into the procedure of changing ladder diagram program to IL language and the procedure of change IL language to target code. This paper studies how to change ladder diagram program to IL with AOV(Activity On Vertex network) and binary tree. And then study the key technology of converting IL to target code by searching the table.(5) We test the edit module and the compile module, which shows this module works well. At last, we take the control system of the dimensional motion platform to test the PLC and its ladder diagram programming system as a whole test. The line and arc trajectory of three dimensional motion platform through teaching, proves the PLC has good motion control performance and good real time performance. It also proves the effectiveness and correctness of the ladder diagram programming system works.