The differences between DCSs and PLCs
The line between PLCs and DCSs is beginning to blur. However, DCSs and PLCs are two separate types of controllers. Due to the differences in the controllers, the overall applications for the controllers are different. To start the exploration between the two types of controllers, it is important to remember that a DCS controller is designed to supervise many PLCs, and as such, they are used to oversee entire processes.
Due to the supervisory nature of DCSs, they are usually not suited for controlling an individual process; they are much too slow. In terms of individual processes, a PLC is much more responsive and capable to make close to real-time adjustments. A DCS, on the other hand, is meant to (and usually does) supervise multiple systems, so it usually cannot handle the quick response time necessary to oversee a singular process.
Though response time is important, a DCS is much more scalable. In short, the number of I/O ports that a...