# Supervision System 4.0 for a Road Tanker Washing Robot Manipulator
## 5 Conclusions  
This paper described the development of the SCADA system for a road tanker washing robot proposed in [18]. The functions assigned to the SCADA system and its architecture characterize it as a fundamental communication center to achieve the intelligent factory concept. The SCADA system allows connecting the entire organization by transferring data between the factory floor and the remaining organizational systems in a bidirectional direction, resulting in added efficiency. The implemented SCADA system integrates a server permanently connected to the Internet, adopts an architecture based on IIoT and allows the development of supervision interfaces that can be accessed remotely via the Internet. The implemented system is also characterized by its high stability and the ability to connect to PLCs from any manufacturer through open protocols widely used in Industry 4.0, such as OPC UA and MQTT. The adoption of new devices to communicate with the robot manipulator can be carried out at any time, thus promoting the M2M concept. Communication with the entire organization is established through a database where the process system and the other organizational software can store and access data. Additionally, the database connection also allows access by big data analysis software to draw conclusions and improve the road tanker washing process. All these functionalities allow easy integration of an FDI system in the SCADA system in the future. To supervise the system, a set of related HMIs were designed in order to target different devices, such as HMI devices, computers, tablets and smartphones, among others. The designed HMIs allow to control and supervise the road tanker washing robot through any devices connected to the Internet, with critical actions being restricted to local devices to guarantee the equipment and the operator's safety. The SCADA system was connected to a photorealistic DT of the road tanker washing robot to test the process operation and the SCADA system functionalities. To guarantee the correct operation of the SCADA system, a system for detecting specifics faults and alarm and reporting modules have been implemented. In this way, it was possible to verify that all functionalities worked as expected. In addition to testing the entire system, the connection between the DT and the supervision system also allows operators to adapt to the robot's operating mode, reducing the learning time when the real system is installed.  
Conceptualization, L.V., F.C., F.M.C., M.J.G.C.M. and J.M.F.C.; methodology, L.V., F.C., F.M.C., M.J.G.C.M. and J.M.F.C.; software, L.V., F.C., F.M.C. and M.J.G.C.M.; validation, L.V., F.C., F.M.C., M.J.G.C.M. and G.C.; formal analysis, F.C., F.M.C., M.J.G.C.M., J.M.F.C. and G.C.; investigation, L.V., F.C., F.M.C., M.J.G.C.M. and J.M.F.C.; resources, F.C., J.M.F.C. and G.C.; data curation, L.V., F.C., F.M.C. and M.J.G.C.M.; writing--original draft preparation, L.V., F.C., F.M.C. and M.J.G.C.M.; J.M.F.C. and G.C.; supervision, M.J.G.C.M., J.M.F.C. and G.C.; project administration, F.C., J.M.F.C. and G.C.; funding acquisition, F.C., F.M.C., M.J.G.C.M., J.M.F.C. and G.C. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Program PORTUGAL2020, grant number POCI-01-0247-FEDER-039764.  
Data Availability Statement: Data sharing not applicable.  
The authors declare no conflict of interest.