As a reaction to the lack of suitable media systems for measurement, control and regulation (PLC) teaching in vocational education and training, the development of the “OmniControl” media system was started in 2011. The aim of the development is a media system that is didactically reduced and easy to use compared to the degree of complexity of industrial “engineering tools”, with which solutions for PLC questions can be created, simulated and also transferred to real structures via a hardware interface.

Concept

The “OmniControl” media system consists of a combination of software and hardware: On the software side, the OmniControl circuit editor has been developed on a Java basis, with which the creation and simulation of circuits is possible by means of IEC-compliant, event-oriented “function block diagram” (FBD) and – in contrast to other media systems – also in the process-oriented “sequential function chart” (SFC). The scope of the easily understandable circuit editor includes standard logic gates, time functions, complex control modules as well as various sources and sinks.

The simulation of the created and/or existing analog and digital circuits takes place directly in the circuit editor or in the models integrated in it: All changes and processes are displayed graphically. Within the model library a selection of models is already offered, which allow the clear representation of basic problems of measurement and control engineering (PLC). The animation of the models includes the control of the circuit by keys/switches/controllers, the visualisation of the processes by displaying the states (e.g.: off/on) and the dynamic changes (e.g. closing/opening the access door, raising and lowering the escalator, changing the volume flows at the air heater and at the tank system). Furthermore, a Y/T writer is integrated which dynamically and continuously displays the control behaviour as a function of time. All circuits created in the editor can be saved, exported and imported.

For hardware communication, the standardized industrial communication protocol “Modbus-TCP” has been embedded in “OmniControl”, by means of which direct communication with industrial input/output modules has been achieved. The advantage of this solution is the possibility of saving cost-intensive industrial PLC hardware and the circumvention of complex and didactically not reduced industrial software tools while retaining the use of hardware models of PLC technology.

On the hardware side, student projects have developed simple and cost-effective Modbus-TCP couplers based on Raspberry Pi and Arduino. The digital and analog sensors and actuators are connected to these bus couplers on the 24 V or 0 – 10 V standard.

OmniControl” is programmed in Java. “OmniControl” can be used on all common operating systems. This distribution concept provides for the software to be made available free of charge for private use and for public institutions.

Outlook

On the didactic level, it is planned that – based on Java technology – application development should be possible in (vocational) school lessons. It would be conceivable, for example, to implement application-oriented programming of software models in the classroom or – after integration of interfaces to web-based techniques – a much simpler visualization of process data via Javascript in HTML.