Enabling Interoperability and Extensibility of Future SCADA Systems∗

Supervisory Control And Data Acquisition (SCADA) systems have been widely used in industry applications. Due to their application specific nature, most SCADA systems are heavily tailored to their specific applications. For example, a remote terminal unit (RTU) that monitors and controls a production well in an oilfield is only connected with a few sensors at the well it resides. The RTU usually collects sensor data at pre-defined intervals, and only sends data back when being polled by a central data server. A user can only access the data in one of the two ways: directly connecting to the RTU in the field or reading from the data server in the control room. A major drawback of typical SCADA systems is their inflexible, static, and often centralized architecture, which largely limits their interoperability with other systems. Wireless sensor networking is a promising technology that can significantly improve the sensing capability of the SCADA system. Sensor networks employ large number of low-cost sensors with easy and flexible deployment, which can largely extend the sensor coverage. For example, in a SCADA system developed for oil and gas fields, the RTUs are usually places at production wells and injection wells. However, there are many other places, such as pipeline, tanks, etc., that have valuable data but are too expensive (e.g., cable requirement) to deploy more RTUs. In such cases, sensor networks are a perfect solution to extend the sensing capability of the SCADA system. However, it is difficult to integrate sensor networks with current SCADA systems due to their limited interoperability. We identify that enabling such interoperability is an important task for future SCADA systems. Another drawback of the current SCADA systems is their limited extensibility to new applications. In the above oilfield monitoring example, a user in the field can only access a sensor’s data by physically going to that well and connecting to its RTU. If the company