Programmable Automation Controller
It is a compact controller that combines the features and capabilities of a PC based control system with that of a typical programmable logic controller (PLC)
Networking typically based on IP and Ethernet
Some examples of applications are building automation,advanced machine control,process control,data acquisition,and equipment monitoring.
Ideally a PAC encompasses the following features-
PLC feel- Modular footprint, Industrial reliability,Wide array of I/O modules and systems configurations.
PC power - Large memory and Fast processing,High-Level data handling and enterprise connectivity,Extensive communications capability,multiple protocols and field network.