Process Control Network (PCN) Evolution

Process Control Network

A Process Control Network (PCN) is a network composed of real-time industrial control systems which manage, monitor and control industrial infrastructure. PCNs make use of software, hardware, networks and their connectivity for accessing, controlling and transferring data with each other. PCNs are also known as Distributed Control Systems (DCS) or Supervisory Control and Data Acquisition (SCADA).

SCADA systems are used in various production environments. To name a few, they are used in power generation, wastewater treatment/purification, transportation systems, oil/gas pipeline/production, wind farms and more.

PCN overview and setup 

PCN networks more or less consist of the following components:

1. Human-Machine Interface (HMI): The Human-Machine Interface (HMI) is a device which shows data to the human operator for monitoring and controlling remotely installed systems. Examples include command-line interfaces, web-based interfaces, touchscreen interfaces and Graphical User Interface (GUI)
2. Programmable Logic Controller (PLC): The Programmable Logic Controller (PLC) is a kind of controller for various processes like water flow and water level, speed, status of valve, temperature and so on. A PLC has a set of inputs for various processes and accordingly produces outputs for controlling them
3. Remote Terminal Unit (RTU): The Remote Terminal Unit (RTU) is a system which is connected to various sensors involved in the process. It converts sensor data to digital form and sends it to SCADA systems
4. Master Terminal Units (MTU): Master Terminal Units (MTUs) is the master of the PCN network. What the CPU is to the computer, MTU is to the PCN. They are central monitoring and control stations which control multiple RTUs placed at remote locations

General overview of PCN communication 

The steps listed below give a small overview of how communication happens in the PCN. They are:

1. End user/operator has access to the Human-Machine Interface (HMI) 
2. The HMI is further (Read more...)