In the water treatment industry, PLC is mostly used, which is an industry habit. In fact, DCS can also be used in places where PLC is used, but the cost of DCS is higher. Considering whether a system uses PLC or DCS mainly depends on the total number and types of I/O and redundancy.

Generally speaking, DCS will be used for systems with more than 500 I/O, or more than 200 analog AI/AO, or for controller and communication redundancy. In the above situation, the cost of using PLC may be higher, and PLC is not very good at analog processing. I hope it helps you.