PLC vs DCS .which one is suitable for your automation system?

  1. Analog vs Discrete I/O and speed

Application with high speed requirement like packaging lines ,machine controls with large

amount of discrete I/O it is clearly a PLC application and other application that require

large amount of analog I/O such as oil and gas ,metals and mining ,pulp and paper they

require distributed architecture with multiple controllers.It is clearly points to a DCS

2.Coordination of Control

You have an application that is contained with in one controller that might lead to you

towards PLC.If you have an application that is distributed across multiple controllers then

you might lead towards DCS

3.Alarm Management

Alarm management in PLCs are somewhat complex . DCS system are architected to handle large amount of alarms.DCS helps to create alarm management strategy.

4.Operator Management

PLCs integrated with lower level devices bring that data up in to the controller and possibly to HMI. DCS is architected to bring that device data and its asset optimization information all the way up through to a higher level packages like maximo or SAP.