Remote - Summer 2013 - (Page 31)

Applications Padre Dam Municipal Water District Upgrades SCADA System with 2.4 GHz Radios Victor Garcia, Staff Writer ProSoft Technology, Inc. Fourteen seconds. Certainly not the type of performance you want from an automobile going zero to 60. Though for a wireless radio system gathering data from more than 70 sites spanning 85 square miles, at extremely varied terrain levels, fourteen seconds is the crème de le crème of performance. The geographical representation is that of the Padre Dam Municipal Water District, located in Eastern San Diego County, which serves several communities from Santee to Alpine. Its terrain ranges from 100 ft. to 2,600 ft. in elevation. Padre Dam MWD decided to go wireless with ProSoft Technology Industrial Hotspot Radios in mid-2010, because it was becoming difficult to maintain its then current system. Its old system, which used RS-232, had a maximum baud rate of 4,800 and took some whopping 90-seconds to get data from all sites. Yes, you read correctly, once every 90 seconds. “The software to drive the original radio system was a custom program written in ‘C Programmable’ by outside contractors. The original authors of the program were no longer available,” said Rich Mellor, Padre Dam MWD SCADA Technician. “There was a great desire to replace the system with one that could be installed and maintained with in-house staff, eliminating dependence on outside contractors.” Between the difficulty maintaining the old system and its speed of response, Padre Dam officials knew it was time to upgrade. After a path study was performed with relatively few issues, installation and configuration of the radios went smoothly. “Along with the radios, we replaced the entire Remote Terminal Unit, including new MicroLogix 1400 PACs, power supplies, terminal blocks and wiring,” said Mellor. There were also some challenges with the terrain. “There are many natural and man-made difficulties, which made line of site an almost impossibility, even though some of our sites are on the highest points around the county,” Mellor explained. “Using some ingenuity and the radio’s repeater ability, we were able to use some of the 900 MHz radios as repeaters allowing us to pass information through very difficult terrain.” ProSoft Technology’s wireless engineers came on site for two days to assist Padre Dam officials with the field study and verify connectivity. After the study, Prosoft helped Padre Dam MWD evolve the system by creating a communications backbone using their 2.4 GHz radios. Nine radios linked in a circular pattern which allowed us to drive communications in either direction should a failure of one radio ever occur. Seven of the nine 2.4 GHz radios are positioned at key sites around the district working with the local 900 MHz radio and PLC to transfer the RTU data gathered back to the office at high speeds. The final two radios are at the office collecting data and storing it in a ControlLogix PLC. At some of Padre Dam’s remote locations there is no AC power. It was decided to go solar in those remote locations. “This was a learning curve, between the size of the panels and the type of batteries. Parabolic antenna mounting also became an issue due to size, angle needed, mounting them back to back, and providing a weatherproof splitter to tie them into a single radio,” said Mellor. The wireless radios were phased in overtime. The final radio was installed in mid-2012. “We had to be careful to not interrupt operations too much,” Mellor said. “Water delivery and storage is a balancing act between demand and weather.” Data from seventy sites in a mere 14 seconds allows the Padre Dam Municipal Water district to respond immediately should one of its Remote Terminal Units shut down, just as what happened in April. “A person driving near one of our RTUs lost control; hit a hydrant and completely destroyed our RTU. Within a just a few seconds, the HMI recorded an alarm of low pressure and total loss of communications with that site,” Mellor said. Knowing what happened and where the incident took place was quick and easy. Data from seventy sites in a mere 14 seconds: quick and easy. For more information visit www.prosoft-technology.com Remote Site & Equipment Management \ Summer 2013 31 http://www.prosoft-technology.com http://www.RemoteMagazine.com http://www.RemoteMagazine.com

Table of Contents for the Digital Edition of Remote - Summer 2013

Editor's Choice
Grid Modernization and Cyber Security Trends
Navigating the Big Data Jungle - How Utilities Can Rise To the Challenge with Analytics
Remote Monitoring: Is it a Global Trend?
Critical Infrastructure, Crital Need
Solutions for Transformer Monitoring
Securing Remote Networks Against Cyber Security – NetFlow to the Rescue
ZigBee Resource Guide
SCADA
Networking
Remote Conference Update
Security
Onsite Power
Industry News
Application Feature

Remote - Summer 2013