Low-energy wireless SCADA used for water application

Water and wastewater utility in Bogotá, Colombia, used an extremely low-power-consumption SCADA system with a data logging support feature, allowing the use of time stamps.

09/22/2011


Low-power wireless technologies help supervisory control and data acquisition (SCADA) communications at the Bogotá, Colombia, water and sewage company, Empresa de Acueducto y Alcantarillado de Bogotá (EAAB). The utility provides services to nearly 700,000 users across the Colombian capital of Bogotá and 11 neighboring municipalities, for a total of more than 7 million inhabitants. EAAB sought a SCADA solution to monitor water pressure in underground pipes with:

  • Report-by-exception (RBE) data acquisition
  • Real-time sequence of events (SOE)
  • Monitoring
  • Reporting
  • Low-energy consumption

Water/wastewater SCADA system in Bogotá, Colombia, operates five zones, each with 70-80 underground sites. Each station measures and alarms water pressure, battery voltage, temperature, intrusion, and inundation. Courtesy: Rugid ComputerThe region was divided into five zones; each zone contained 70-80 underground sites. Each station needed to measure water pressure (primary interest), battery voltage, temperature, intrusion, and inundation. When any value is not within normal range, an alarm code should be generated.

Choosing the correct remote terminal unit (RTU) was an essential part in a project of this scale. Compax International did a market study; the project subcontractor awarded the solution to an extremely low-power-consumption (2 mA at full operation) solution that supports data logging and a protocol allowing the usage of time stamps.

Each station cabinet for water/wastewater in Bogotá, Colombia, houses three main devices, the RTU, a cellular modem as the primary means of data transmission, and a WiFi server as a backup means to retrieve data. Courtesy: Rugid ComputerEach station cabinet houses three main devices, the RTU, a cellular modem as the primary means of data transmission, and a WiFi server as a backup means to retrieve data. Each site is housed underground so physically accessing the RTU to retrieve data was impractical.

Rugid Computer Inc. provided its RUG3 RTU, designed for remote data acquisition and control applications. It incorporates advanced hardware and software techniques to implement an application in minimal time. Courtesy: Rugid ComputerEach site was designed to operate at the most efficient manner possible for energy usage, physical costs, and data costs. To achieve these goals, the RTU takes measurements every 10 minutes and stores the data in its logging memory. Data transmits once every 6 hours. When a transmission is initiated, the RTU turns on the modem, data is transmitted, and the modem is turned off. In the case of an out-of-range value, the rule of transmitting every 6 hours is bypassed, and data transmits immediately to the control station. Due to this report-by-exception based protocol, a sequence of events analysis can be generated.

Wireless communication

Rugid Computer WiSI—Wireless Sensor Interface is designed for rapid deployment to monitor and control remote sensors; WiSI is an all-in-one radio, data acquisition and control, self-powered device; all enclosed in a weatherproof, IP67-rated outdoor, hand-To reduce the amount of data and related costs associated with transmitting the data via the cellular network, Rugid Computer and Compax International collaborated to devise a means by which multiple floating-point values were scaled and packed into one 16-bit integer. Additionally, Compax International used Rugid Computer’s RUG9 communication protocol, instead of MODBUS, due to the better data efficiency. To interface with the HMI software, Wizcon (now part of emation AG), at the zone control station, required Compax International to develop a custom driver. The driver enables the connection of unlimited devices over TCP/IP without communication error or system overload. Additionally a designated SQL server was assigned. The SQL server receives the data from each zone server, and authorized users can access the system from anywhere through a standard web browser.

-Cheryl Melchior is vice president of visual design and engineering with Rugid Computer Inc., Olympia, Wash., and Meidad Vaknin is with Compax International (93) Colombia LTD, Bogota, Colombia. Edited by Mark T. Hoske, CFE Media; posted by Chris Vavra, Control Engineering, www.controleng.com 

www.compax.com.co 

www.emation.ch/index.php?id=27&L=2 

www.rugidcomputer.com 

www.rugidcomputer.com/rug3.htm 



No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.