## 6 Discussion and Conclusions  
Dual architecture is commonly used to achieve the required SIL of electronic control systems. However, its implementation is typically at the firmware level of control systems. The proposed methodology enables the implementation of a dual architecture at the application level.  
This paper deals primarily with safety integrity against systematic software failures. This contribution deals with the integrity of safety against accidental failures only to the extent of demonstrating that this problem will not be an obstacle in the implementation of a dual architecture. This paper is not about cyber security. If the dual architecture was connected to a publicly available network (e.g., the Internet), the issue of cyber security must also be addressed. Stimulating information on this issue can be found in ref. [27].  
Figure 8: Function block of the comparator (**a**) and function block of the “Muting” safety function (**b**).  
The possibility of implementing safety functions modelled and simulated in the Matlab Stateflow software environment can be considered the main benefit of the proposed method. The solution for the implementation of safety functions in industrial applications with the possibility of their modelling and simulation is not yet commercially available, and functional safety testing can only be carried out after the system has been programmed. At the same time, testing is a very important mechanism for detecting systematic software failures. Thanks to the solution proposed in the paper, testing can be performed even before the system is implemented, which can save a significant part of the costs because systematic faults can be detected and eliminated during the design phase and not after the hardware implementation of the control system.  
A Simatic PLC of the S7-1500 series (company Siemens, Berlin, Germany) was used as dual architecture hardware. However, the method is universal and can be applied to PLCs of other manufacturers or other hardware platforms. The verification of the proposed methodology also took place on other safety functions and hardware platforms, but for the sake of clarity, only the selected platform and the selected safety function are listed.  
The acquired knowledge can also be used in the creation of more complex architectures of control systems (2003) to positively influence not only the safety but also the availability of the control system.  
Conceptualization, [PERSON]; data curation, M.M.; formal analysis, [PERSON]; funding acquisition, M.G.; investigation, [PERSON]; methodology, M.M. and J.Z.; project administration, [PERSON]; resources, M.G.; software, M.M.; supervision, [PERSON]; validation, [PERSON]; visualization, [PERSON]; writing--original draft, [PERSON]; writing--review and editing, [PERSON] All authors have read and agreed to the published version of the manuscript.  
This work was supported under the project of Operational Programme Integrated Infrastructure: Independent research and development of technological kits based on wearable electronics products as tools for raising hygien standards in a society exposed to the virus causing the COVID-19 disease, ITMS2014+ code 313011 ASK8. The project received co-funding from the European Regional Development Fund.  
Not applicable.  
All necessary data is given in this article. (Generated from equations).  
The authors declare no conflict of interest.