Open environment for programming small controllers according to IEC 61131-3 standard

Abstract

A control engineering environment called CPDev for programming small controllers in ST, FBD and IL languages of IEC 61131-3 standard is presented. The environment consists of a compiler, simulator and hardware configurer. It is open in the sense that: (1) code generated by the compiler can be executed by different processors, (2) low-level components of the controller runtime program are developed by hardware designers, (3) control programmers can define libraries with functions, function blocks and programs.

Of the three IEC languages, ST Structured Text is a basis for CPDev. FBD diagrams are translated to ST. IL compiler uses the same code generator. The runtime program has the form of virtual machine which executes universal code generated by the compiler. The machine is an ANSI C program with some platform-dependent components. The machines for AVR, ARM, MCS51 and x86 processors have been developed so far. Applications include two controllers for small DCS systems and PC equipped with I/O boards. CPDev may be downloaded from http://cpdev.prz-rzeszow.pl/­demo.