What are the differences between SCADA and DCS?

What are the differences between SCADA and DCS?

· A SCADA system is event driven, while a DCS is state driven.

· RTUs for SCADA and PLC/Controllers for DCS

· DCS is process oriented and SCADA systems are data-gathering oriented

· The DCS (Distributed Control Systems)is usually used in factories and uses a high-speed communications The SCADA system covers larger geographical areas.

· A SCADA considers changes of state as the main criteria for the data gathering.

· DCS systems consider the process variable’s present state to be the main criteria driving the DCS and tasks are generally run sequentially, rather than event driven. Therefore alarms & events are not generated when a point changes state, but when the particular process run.

Difference Between DCS & SCADA


  • DCS (Distributed Control System)
  • DCS is process oriented
  • DCS is processing state driven
  • DCS is commonly used to handle operations on a single locale
  • DCS (Distributed Control Systems) is usually used in factories and uses high-speed communication, distributed controllers are essential.


  • SCADA (Supervisory Control and Data Acquisition)
  • SCADA is Data Acquisition oriented
  • SCADA is event-driven
  • SCADA is preferred for applications that are spread over a wide geographic location
  • SCADA systems are used to monitor or to control chemical, physical or transport processes.