Hardware-in-the-loop (HiL) tests allow building and plant controls to be tested for correct and efficient operation, both before commissioning and during later control optimization. This requires the plant or building to be represented as a digital twin in a simulation model, which can be created using SimulationX and the GreenCity Library, for example. A Functional Mockup Unit (FMU) can then be integrated into the simulation model to provide a connection to the real controller through EASD’s SimBus. SimBus communicates with the controller through a choice of interfaces.
The controller receives the input values simulated by the digital twin. At the same time, SimBus transfers the control outputs calculated by the controller to the digital twin through standard simulator coupling interfaces such as FMI. HiL tests can also run faster than real time to investigate longer periods efficiently.
Supported Platforms and Interfaces
- CoDeSys 2 and 3 (e.g., SABO, Wago)
- Modbus (master and slave)
- Python, including an extensive wrapper framework
- Java, including a framework
- NetLogo (multi-agent system)
- FMI (functional mockup units)
- Further interfaces in preparation
EASD SimBus Function Overview
- Coupling of real control electronics (e.g., PLCs) with a digital twin
- Investigation of control reliability and efficient operation before commissioning or after code changes
- Safe testing of critical system states on a computer
- Investigation of controls faster than real time
- Communication with the controller through Modbus TCP/IP (further interfaces in development)
- Communication with the digital twin through FM
The following examples illustrate different simulation couplings:
Direct Software Coupling
Direct software coupling enables reliable and precise testing of algorithms and software modules.
Coupling Through Modbus
Modbus coupling enables model-based development and testing of controllers without additional hardware.
Coupling Through CANOpen
CANOpen coupling enables model-based control development without requiring changes to the PLC logic (variable mapping).