Jan Sadolewski

Architecture of FPGA Embedded Multiprocessor Programmable Controller

This paper presents the design and implementation of a multiprocessor programmable controller in field-programmable gate array (FPGA). The novelty of the proposed solution is that it combines two approaches used so far in the domain of FPGA implementations of control algorithms, i.e., program based and hardware coded, and applies multiple processors in a single FPGA chip. The controller is programmed according to the IEC 61131-3 standard and runs control tasks in parallel. Performance tests of the prototype show that it is able to execute control programs significantly faster than industrial programmable logic controllers.

CPDev Engineering Environment for Modeling, Implementation, Testing, and Visualization of Control Software

The paper presents the CPDev engineering environment, which is a comprehensive set of integrated tools for programming PLCs, PACs, and DCSs, according to the IEC 61131-3 standard. The environment supports various parts of the project development, including modeling (using SysML diagrams), implementation (with IEC 61131-3 textual, graphical, and mixed languages), testing (by textual, table, and performance tests), simulation (in off-line mode), debugging (with tracing variable values and breakpoints), hardware resources configuration, execution (either on the virtual machine or FPGA-based hardware machine), as well as visualization. The CPDev project is designed in a way supporting portability. Therefore, prepared control programs can be run on any supported target platform, such as AVR, ARM, and x86. The environment has a few applications, both industrial and laboratory.

CPDev engineering environment for control programming

Programming a control example by CPDev tool using LD, FBD, and SFC graphical languages of IEC 61131-3 standard is presented. Another example demonstrates the use of data structures and arrays of function blocks in ST textual language. The two parts indicate that CPDev provides now essential functionalities specified in the standard. Remarks how the tool relates to established engineering environments such as CoDeSys, STEP 7, Control Builder F, and ISaGRAF are also given.

IEC structured text programming of a small Distributed Control System

A prototype environment called CPDev for programming small distributed control-and-measurement systems in Structured Text (ST) language of IEC 61131-3 standard is presented. The environment consists of a compiler, simulator and configurer of hardware resources, including communications. Programming a mini-DCS (Distributed Control System) from LUMEL Zielona Gora is the first application of CPDev.

Interfacing Inputs and Outputs with IEC 61131-3 Control Software

The paper presents interfaces for handling inputs and outputs from IEC 61131-3 control software available in the CPDev engineering environment. The programmer can use code-embedded clauses which directly connect addresses of variables to particular I/Os. Another approach is to perform additional configuration step to map the variables to hardware channels, what is especially convenient when external modules are used. I/O function blocks are yet another possibility to connect variables to inputs and outputs. The blocks may be either generic or specialized for particular purposes such as fieldbus communications or to perform additional signal processing.

OPC Data Acquisition Server for CPDev Engineering Environment

OPC Server has been created for the CPDev engineering environment, which provides classified process data for OPC client applications. Hierarchical Coloured Petri nets are used at design stage to model communications of the server with CPDev target controllers. Implementation involves an universal interface for acquisition data via different communication protocols like Modbus or .NET Remoting.

LD Graphic Editor Implemented in CPDev Engineering Environment

Process of creating a diagram in LD graphical language in CPDev environment, translation to ST textual program, compilation into VMASM executable code and, finally, simulation is overviewed by means of typical example. Earlier version of CPDev LD editor did not suit industrial applications, particularly with respect to processing other variables than boolean. Basic functionalities of LD in CPDev are now not far apart from those of renown CODESYS package.

Structure and Functionalities of Ship Autopilot Simulator

Heading control, track control, rate of turn and turn radius are basic maneuvers executed by ship autopilots. The paper presents structure and functionalities of an autopilot simulator, written in ST language in CPDev environment. It runs both on PC and on ARM-based controller for anticipated real-time tests. Sample results of ship dynamics identification through zig-zag maneuver and of wave filtering by an observer are presented. The simulator has been developed in cooperation with a Dutch company.

Object-Oriented Approach to I/O Handling in Control Programs

The paper shows how new object-oriented features introduced in IEC 61131-3:2013 can be used for handling inputs and outputs. The new extensions such as classes, interfaces or inheritance are first characterized. Then, an UML model of I/O handling with diagrams for peripheries, universal data type and board capabilities is given. Finally, a practical example of model implementation is shown with portions of ST code accessing three different types of I/O boards.