PLCs and PACs simplify data acquisition September 2024 PLCs, DCSs & Controllers By Jeff Payne, product manager, PLC, I/O and PC-based controls, AutomationDirect. Data acquisition, data logging, and data analysis are required functions for most modern industrial control systems. The simplest and lowest-cost way to provide these functions is often by using the same platform providing real-time control, namely the PLC or the programmable automation controller (PAC).