The SCADA industry was born out of a need for a user-friendly front-end. The need was to control a system containing Programmable Logic Controllers (PLC SCADA). This supervisory system allows remote monitoring and control of an amazing variety of devices in industrial plants. This includes water and gas pumps, track switches, and traffic signals.
One of the key processes of SCADA is the ability to monitor an entire system in real time. This happens via data acquisition, or collected data. These include meter reading and checking statuses of sensors. These data points are communicated at standard intervals depending on the system.
Besides the data being used by the RTU, it is also displayed to a human. The human is able to interface with the system to override settings or make changes when needed.
Modern systems have many data elements called points. Each point is a monitor or sensor and these points can be either hard or soft. A hard data point can be an actual monitor.
A soft point is an application or calculated value. Data elements from hard and soft points are usually always stored and logged to create a timestamp or history.
In essence, a SCADA application has two elements. They are:
Throughout this article, I'll also cover other concepts related to the application of this system.
There are three main elements to any system:
Each RTU collects real-time data at a site. Communications bring that information from the various plant (or regional RTU sites) to a central location. They can also return instructions to the RTU.
Communication within a plant is conducted by data cable, wire or fiber-optic. Regional systems most commonly utilize radio. The HMI is a PC system running powerful graphic and alarm software programs.
The HMI software displays this information in an easy to understand graphics form. It archives the data received, it transmits alarms, and it also permits operator control as required.
Now, the initial question of "What is SCADA?" has been answered, the next step is to look at the way this system operates as a network.
A SCADA network consists of one or more Master Terminal Units (MTUs). These are utilized by staff to monitor and control a large number of Remote Terminal Units (RTUs). The MTU is often a computing platform, like a PC, which runs specialized software. The RTUs are most likely small devices that are hardened for outdoor use and industrial environments.
As we saw earlier, there are several parts of a working system. This system usually includes signal hardware (input and output), controllers, networks, user interface (HMI), communications gear and software. Altogether, the term SCADA refers to the entire central system. The central system usually monitors data from various sensors that are either in close proximity or off-site (sometimes miles away).
A SCADA system performs four functions:
These functions are performed by several kinds of SCADA components:
There are five phases in creating a functional system:
A complex SCADA system can be complex to configure. However, it is usually much easier to operate.
Modern SCADA systems are an extremely advantageous way to achieve industrial process monitoring and process control. They are great for small uses, such as climate control. They can also be effectively used in large applications. This could include monitoring and controlling a nuclear power plant, oil and gas plant, or transit system.
SCADA can come in open standard communications protocols. Smaller systems are very affordable. They can be purchased as a complete system. They can also be mixed and matched with specific components.
Large systems can also be created with off-the-shelf components. SCADA software can also be easily configured for almost any application, removing the need for custom software development.
As demonstrated in this knowledge base, building the right system for your business isn't simple. It's easy to spend too much money on unnecessary features and capacity, but we can help you improve efficiency in ways you probably haven't thought of.
It's hard to learn everything you need to know and still perform your daily job. We can help you plan your SCADA implementation, with expert consultation, training and information resources. DPS telemetry gear is built with the capabilities and capacity you need. We're committed to helping you get the best monitoring system for your specific needs.