You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective 
Chapter Title:  1) DISTRIBUTED CONTROL 
1. Abstract of Cited Paper (BIB001):  Fractional-Order Proportional-Integral-Derivative (FOPID) controllers presents a natural extension to PID controllers, which have been used profusely in industrial control systems, and are of great practical preference. This paper presents an implementation of FOPID control in an industrial distributed control system (DCS) that is used here for level process control. The setup is composed of ABB DCS AC 700F2 (the controller) connected to Lab-Volt Level Process Station (the plant). To implement an FOPID controller for this setup, a function block is built in the industrial controller using a certain discrete form of FOPID control. A comparison of the system response using FOPID and conventional PID controllers is performed via simulation (using a response optimization tool) and experimentally (using the setup). The results show a relative improvement in system response using FOPID control.

Literature Review:
The distributed control system (DCS) is one example of the general category of decentralized control systems. DCS is often designed to control the industrial process or production in one location, and can include electricity generation plants, oil refineries, and factory manufacturing, among others. For production and process control, the DCS can oversee multiple subsystems with supervisory level control, and controls the processes in subsystems BIB001 . Specifically, in DCS, controllers are deployed to provide specific production and process. Various controllers work together to carry out production or processes collaboratively. Such collaboration is enabled by a supervisory control loop to connect various localized controllers. DCS operates a plant or a factory by various functional groups (FGs) that work together to accomplish the designated control missions. The different FGs perform segregated tasks and functions to improve productivity and efficiency. For example, as shown in a recent work by El-Shafei et al. BIB002 , the liquid level process control plays an important role in PA systems. The authors implemented a DCS-controlled process station in a simulation environment for the study of liquid level process control. In their study, the control performance of DCS was compared with different proportional-integralderivative (PID) controllers. In addition, the programmable logic controller (PLC) is a system that plays the crucial role of providing regulatory control for specific applications. Particularly, PLC interprets signals from sensors and generates and transmits control signals to actuators corresponding to the targeted set points. As a standalone system, PLC is usually configured especially for specific tasks.