SCADA vs. DCS

With SCADA the information is largely just gathered and presented; the "S" stands for "supervisory". With DCS, some interaction between the presentation point and the process controller is to be expected, as are interactions between individual controllers vis the DCS.

The boundary between the two terms is somewhat blurred.

SCADA usually refers to a central system that monitors and controls a complete site or a system spread out over a long range. The remote site is usually controled by RTU, PLC, or could be a DCS. The host or main control functions are done through the SCADA host controller on supervisory level capability.

DCS has a full functionality with multiple I/O. Usually the main controller and the I/O cards installed in a rack room or the I/O could be installed in remote locations and interface to the main DCS controller. as SCADA the field (remote) controllers could be interfaced with the DCS host controller, however DCS is mainly support its own remote I/O.

Still not clear for me. SCADA allows control and monitoring DCS as well? Which one is more advantageous for controling and rapid response of the process?

SaC.

SCADA, which has been around for some time is analog based. My experience was that it is solely a single-function on/off true/no true ok/fault arena.

I seem to see that DCS is digital, in that the two-way transmissions as digital, and within that can handle multitple channels of data status, not just on/off but incremental data like acutal temperature from a specific location.

Thus, in a community locale, a single-channel/broadband RF connection can be in place instead of multiple-channel or polled single channel exchange of data with otherwise limited capabilities.

Hope this is on queue for you.

Motorola C&E was doing SCADA, providing utilities for many years and may have migrated to this newer technology. I haven't checked.