The Research And Manufacturing Of Embedded PLC Programmer

Research of any project is the result of science and technology development of a certain historical era and it is subject to the constraints of technology level at that time. With the rapid development of computer technology, embedded technology, memory technology the advanced science and technology to the programmable logic controller (PLC) in the development programmer may expand the memory capacity, more flexible communication, higher reliability, improving the function of the programmer and so on. Therefore, the purpose of this research project proposed a new embedded PLC programmer device to meet the requirements of modern industrial control development, developing and applying PLC in our nation is very meaningful.In this paper, ARM (Advanced RISC Machines) is used as the control center, applying data structure theory, software engineering theory, operating systems theory and embedded technology and so on, researching and designing a new type device of embedded PLC Programmer, the main results obtained are summarized as follows:(1) The master chip LPC2478 is used as the core which set up PLC hardware platform, it includes the keyboard module, LCD module, memory module, power management module, communication module, etc, reserved for expansion interfaces for connecting with other peripherals.(2) The embedded operating system uC/OS-II is used as the core which established the PLC programming software system, it achieves the function of editing, modifying, deleting, searching, inserting, saving and compiling the PLC instruction, communicationing with small PLC realizes to transport PLC program code, monitor the operational status of PLC and download the object code from the PLC host etc, they have the function of good man-machine interface.(3) According to the new system design planning book with the 32 basic instructions and step instruction and applying data structures theory (such as the knowledge of binary tree, insertion sort algorithm and binary search algorithms,etc.) and compiler theory (such as finite automata theory, etc.) which research the compilation algorithms and decompilation algorithms of the PLC instruction statement.(4) Realizing communication with the computer by asynchronous serial interface or USB-CAN200 adapter, In addition, writing code with the associated application, implementing to convey the object code from ARM to the computer, in the computer these object code decompiled are displayed. By writing PLC code in the computer compile it, it is passed to ARM device and it decompiles these object codes from PC and shows PLC source code.(5) According to the requirements based on friendly interface design it design the password entry interface, the main interface, PLC interface command statement processing, keyword search interface, communications interface and so on.(6) The system tasks are allocated according to the system function, the priorities of the task are determined according to the importance of the task, which design the system boot and loader program and establish a system message queue and delivery mechanisms.(7) The system function of the PLC programmer device is tested, the performance of the PLC programmer device is tested, the reliability of the PLC programmer device is tested, the results obtained have reached the requests.