Ken Moore
Lifetime Supporting Member
I have/do work with both. The biggest differences in my opinion are.
1. DCS systems do fault tolerance and redundancy much better. The PLC's are not close...yet.
2. It is much easier to do complex controls with a DCS, yes you can do the same thing with a PLC, but it takes a lot more code.
3. Only one tag database in most DCS systems. With a PLC/SCADA system, each has there own list of "tags".
4. PLC/PAC controllers are much faster, but hold less. Most DCS systems have 100msec scans or slower.
1. DCS systems do fault tolerance and redundancy much better. The PLC's are not close...yet.
2. It is much easier to do complex controls with a DCS, yes you can do the same thing with a PLC, but it takes a lot more code.
3. Only one tag database in most DCS systems. With a PLC/SCADA system, each has there own list of "tags".
4. PLC/PAC controllers are much faster, but hold less. Most DCS systems have 100msec scans or slower.