The Design and Realization of Virtual Machine of Embedded Soft PLC Running System

Abstract

Currently soft PLC has been the focus of study object for many countries. Soft PLC system consists of the developing system and running system. A Virtual Machine is an important part in running system even in the whole soft PLC system. It explains and performs intermediate code generated by the developing system and updates I/O status of PLC in order to complete its control function. This paper introduced the implementation scheme and execution process of the embedded soft PLC running system Virtual Machine, and mainly introduced its software implementation method, including the realization of the input sampling program, the realization of the instruction execution program and the realization of output refresh program. Besides, an operation code matching method was put forward in the instruction execution program design. Finally, the test takes PowerPC/P1010 (Freescale) as the hardware platform and Vxworks as the operating system, the system test result shows that accuracy, the real-time performance and reliability of Virtual Machine.

Keywords

• Embedded soft PLC
• Virtual machine
• Running system
• Instruction execution.