What are some advantages of SCADA over other protocols?

SCADA (supervisory control and data acquisition system) refers to the combination of telemetry and data acquisition. SCADA encompasses the collecting of the information via a Remote Terminal Unit, transferring it back to the central site, carrying out any necessary analysis and control and then displaying that information on a number of operator screens or displays. The required control actions are then conveyed back to the process.

SCADA communication protocols are developed for utility requirements. The frame structure is well defined for polling of data.

A protocol is simply the rules that govern the data transfer between parts of a control system. Different protocols have varying strengths and weaknesses.

This document looks at the ideas behind good protocols for the users of SCADA / telemetry systems. This is an area often neglected by users when first investing in a SCADA system, as they are often happy to get any data from remote stations. However, it is important to give protocol choice proper consideration.

There is a Human Machine Interface that can be done through Local and Supervisory Protocols