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Fiber Optic Security Control and Data Acquisition (SCADA) Networks

SCADA (Supervisory Control And Data Acquisition) networks, originally developed in the 1960s, are used for industrial measurement, monitoring, and control systems, especially by electricity and natural gas utilities, water and sewage utilities, railroads, telecommunications, and other critical infrastructure organizations. They enable remote monitoring and control of an amazing variety of industrial devices, such as water and gas pumps, track switches, and traffic signals. A SCADA system gathers information, such as where a leak on a pipeline has occurred, transfers the information back to a central site, alerting the home station that the leak has occurred, carrying out necessary analysis and control, such as determining if the leak is critical, and displaying the information in a logical and organized fashion. SCADA systems range from relatively simple networks that monitor environmental conditions of a given location to incredibly complex systems that monitor all the activity in a power plant or a municipal water system. for example.

SCADA Network Components

A SCADA network consists of one of more Master Terminal Units (MTUs) which the operators utilize to monitor and control a large number of Remote Terminal Units (RTUs). The MTU is often a general purpose computing platform, like a PC, running SCADA management software. The RTUs are generally small dedicated devices which are hardened for outdoor use and industrial environments. Fiber optic data transceivers are ideal in SCADA networks because they offer EMI immunity. When transceivers are used for the master and remote terminal units, a fault tolerant self-healing ring network is easy to configure. Figure 1 illustrates a self-healing ring network topology.

Figure 1— Self-healing Ring Network

Self-healing Ring Network

Reliable operations of SCADA systems depends on proper configuration, cyber security measures, and other factors.