PURPOSE

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The purpose of this specification is to define the network architecture for SCADA systems used in Critical Infrastructure (CI) sectors.  

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SCOPE

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The scope will be limited to the most commonly used network configurations used within the following CI sectors: Electricity subsection within Energy; Water and Wastewater; Rail subsection within Transportation; and Emergency 911 system subsection within Emergency Management Communications.

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OVERVIEW

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Industrial Control Systems (ICS) are different systems, networks, devices and controls that are used to automate, operate, and collect data on industrial processes. ICS systems are used in nearly every industrial and critical infrastructure sector today, which include transportation, power, water treatment, communication, and emergency management. Each industry will use ICS systems differently depending on the tasks that are required. Some of the different types of ICS used by these industries include supervisory control and data acquisition (SCADA) systems, distributed control systems (DCS), and Programmable Logic Controllers (PLC). 

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Industrial Control Systems contain control loops, human interfaces, remote diagnostics and maintenance tools that are connected through multiple network protocols and network architectures. Control loops use sensors, actuators, and controllers to handle different processes. The sensor produces a measurement and sends the data to the controller. The controller interprets the signals and creates similar variables with an algorithm, then creates target set points. These are transmitted to actuators, which are control valves, breakers, switches, and motors that are used to manipulate the process based off of commands defined by the controller. To monitor and configure the set points, operators use Human Machine Interfaces (HMI) to control the algorithms and adjust the parameters of the controller. The HMI shows process status and historical information. Diagnostics and maintenance tools are used to identify, prevent, and recover process failures.