What is a SCADA System and How Does it Work?


DURATION 4 minute read

What is a SCADA System?

Supervisory control and data acquisition (SCADA) is a system of hardware and software elements used to control processes both locally and remotely. SCADA networks contain computers and applications that are key to providing essential services, such as electricity, water, wastewater treatment, and transportation. They are crucial for organizations as they help maintain efficiency, process data for more well-informed decisions, and communicate system issues to help mitigate loss and downtime.

SCADA systems perform:

  • Data Acquisition and Communication
  • Information and Data Presentation
  • Monitoring and Control

These functions are performed by sensors, remote terminal units (RTUs), controllers, and a communication network. The sensors collect the information, RTUs send the information to the controller, which displays the status of the system. The operator can then give commands to the components of the system depending on the status.


Data Acquisition and Communication

SCADA systems allow communication between the operator and the connected devices. Real-time systems have thousands of components and sensors, each gathers data and helps ensure that every part of a facility is running effectively. The real-time applications can also be controlled remotely.
Access to real-time information allows entities to make data-driven decisions about how to improve processes. Without SCADA, it would be difficult to gather sufficient data for consistently well-informed decisions.


Information and Data Presentation

Normal circuit networks have some indicators visible to the operator, but real-time SCADA systems have thousands of sensors and alarms which would be impossible for a human to handle simultaneously.
SCADA systems use a human-machine interface (HMI) to display the information gathered from the various sensors, which allows the operator to process the data. The HMI provides multiple control units, such as programmable logic controllers (PLCs) and RTUs. The HMI provides a graphical representation of the system. For example, there may be an image of the pump connected to the tank, which allows the operator to see the flow and pressure of the water in that tank in real-time.

Additionally, the HMI utilizes an alarm system, which is activated according to predetermined scenarios. For example, if a water tank has an alarm set at 50% and 65% capacity and the water reaches higher than the 50% mark, the alarm will give a normal warning. However, if the water reaches above 65%, the alarm will go critical.


Monitoring and Control

SCADA systems are typically designed to be automatic, but critical situations may require human intervention. SCADA systems utilize different switches to operate each device and to display the status in the control area. Any part of the process can be turned on or off from the control station using the switches.

A SCADA system will quickly notify an operator if the water pressure changes in a specific area. The operator can pause the operation and view system data via an HMI to determine the cause of the issue. The operator may discover that a pump was malfunctioning. The SCADA system’s ability to notify the operator of an issue allows the operator to quickly resolve the issue and minimize any impacts.

Additional Uses

Several cities and municipalities have begun leveraging SCADA for sewer diversions, wet well protection, and to provide early flood warnings through strategically placed sensors. The versatility of SCADA systems allows for creative and innovative ways to gather and monitor data and control systems.

Our team designs, installs and maintains SCADA systems that improve performance, grow with facilities, and provide long-term stability and cost control. Contact us if you have any questions regarding implementing or updating SCADA systems.



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