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Olsson harnesses SCADA technology

Wednesday, January 21, 2015

Warren Humphrey, Automation and Technology

An engineer in Kansas City, Missouri, receives an alarm on her cell phone that there has been an equipment failure at her wastewater treatment plant in Springfield. A utility superintendent remotely logs in from home to check on a problem with the city water supply. An electrical line worker can monitor re-closer faults from his office computer. All of this is possible because of Supervisor Control and Data Acquisition (SCADA) technology, and it may be one of Olsson Associates’ best-kept secrets.

Olsson has been specifying and designing SCADA systems for decades as a part of water, wastewater, and electrical utility design projects. For the past 15 years, however, Olsson has been offering SCADA integration services systems in addition to traditional design. 

SCADA has been around for more than 70 years and can mean different things to different people. A SCADA system can be as simple as monitoring a water tower level to turn on wells or as complex as an advanced treatment plant control system. Whatever the application, a SCADA system adds operation consistency, maintenance savings, and management confidence. To see an example of the SCADA architecture of a wastewater treatment plant, click here.

All SCADA systems are made up of some combination of a few common components. These components include the following:

  • Field Devices. Field devices are equipment that turns process information into an electrical signal. Such equipment includes transmitters, switches, motor starters, and variable frequency drives (VFDs).
  • Inputs/Outputs. Inputs/Outputs (I/O) are electronic components that translate the field device signals into electronic data that can be processed by the controller.
  • Controller. The controller is the “brains” of the system. The controller reads inputs from field devices, executes logic code to make decisions, then sends commands to output field devices. An example of this would be a well control system. The water tower level is transmitted to the controller, where it is compared to well start and stop setpoints. If the level is low, the controller sends a command to start a well pump. If the level is high, the controller sends a command to stop the well pump.
  • Telemetry. Telemetry is another term for communications. Telemetry can be physical media like the wired cables of the Ethernet. Telemetry can also be wireless such as data radio or a cellular modem. In many SCADA systems, the field devices and I/O are a great distance from the controller. In these cases, telemetry is necessary to bridge this gap.
  • Host System/HMI. A host system or human machine interface (HMI) provides the system’s visuals to operators and other SCADA users. Host systems can be computer graphic screens, alarms, trend charts, and reports.

There are often dozens of ways to build a SCADA system, as several factors must be taken into account. These factors include such things as compatibility, complexity, hardware and software vendor reputation, and telemetry. Cost, of course, is another factor. Since Olsson is not aligned with any one hardware or software manufacturer, our team can focus on the main objective of solving our clients’ challenges with the best possible solution.

Oftentimes, when Olsson is brought onto a project, team members learn a client has an existing SCADA system. In these cases, Olsson’s role is to design and communicate exactly what is needed to expand or modify the system. Such tasks often include working with an existing vendor or integrator to make sure all bases are covered.

Whatever clients’ SCADA needs, Olsson is prepared to handle them with quality and expertise. Our integration services include SCADA programming, startup, training, documentation, and support.

Having all of these services under one roof enables us to provide the quality and comprehensiveness that our customers need and deserve. If you have any questions regarding Olsson’s SCADA services, please contact Warren Humphrey at 402.458.5942 or whumphrey@olssonassociates.com.

Example host system

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