Providing timely actuation guarantees with heterogeneous SAN for industrial process control

When wireless sensor networks are introduced in industrial settings, they will be part of a much larger heterogeneous sensor and actuation network that includes those sub-networks together with Ethernet cabled Programmable Logic Controllers (PLCs) and control stations. Performance issues arise in such systems. Particularly, actuation latencies are considered crucial in those scenarios. In this paper, we present an approach for planning and evaluating a heterogeneous supervisory control and data acquisition (SCADA) system with wireless sensor networks. We propose closed-loop schemas and mechanisms for measuring and verifying the latency bounds in the whole system. As a case study, we deploy and evaluate our approach on an oil refinery, where several heterogeneous networks are used to monitor and control a water treatment process. Results demonstrated the effectiveness of our method in planning, debugging and providing feedback about the network (in)ability to provide timely actuation guarantees.