| Summary: | 碩士 === 國立中正大學 === 機械系 === 91 === Traditional programmable logic controllers use a closed architecture which subjects users to the limitations of the software and hardware and makes it impossible for them to integrate different kinds of PLCs. Therefore, we use a PC-based open architecture and employ various functions of a real-time, multi-tasking Linux operatiing system to develop multiple modules of a PC-based SoftPLC real-time control system. The system integrates four software modules, which include an editor, an interpreter, an off-line simulator, and a real-time controller.
The PLC editor is used to develop a ladder program which conforms to the standard International Electrotechnical Commission (IEC61131-3) programming languages. A mouse and keyboard lets the user design the needed program. The ladder program can then be translated into another standard IEC61131-3 language, that is, an instruction list (IL). Finally, we enter the IL into the interpreter, combine the driver, and use the XY table to test the logic of the program ladder. Thus, the application of a PC-based SoftPLC in a real-time control system is realized.
|
|---|
