Digi XBee Enables Street Light Management System
CIMCON Software, a leading developer of automated street light control systems, helps communities reduce the maintenance cost and environmental footprint of street lights. CIMCON's LightingGale system replaces traditional street light photocells with a Street Light Controller (SLC). The SLC can monitor pertinent electrical parameters and control the light in a variety of ways – from dimming the lights during peak hours to setting schedules so groups of lights can be turned on and off at set times to conserve energy. The system can also send alerts when something goes wrong. This eliminates the need to physically inspect the system on a regular basis which greatly reduces maintenance costs.
To overcome these issues, CIMCON chose Digi's XBee-PRO® ZB module for the project because of its rugged design, ease of use and reliability.
Business Challenge
CIMCON needed a rugged mesh networking solution to connect island street lights and remote electrical monitoring reclosures across the entire island of St. John, a mountainous region with dense vegetation, warm temperatures, high humidity, regular thundershowers and a hurricane season. Under these conditions, CIMCON felt the highest risk would be the communication between the SLCs and the gateway.
"We needed something that was easy to use and could withstand the harsh elements," said Anil Agrawal, director, CIMCON Software. "We also needed a solution that could traverse great ranges and dense brush. Digi offers the industry's leading ZigBee products, and we felt confident its XBee® modules would prove reliable under the severe island conditions. In addition, Digi's K-Node service allowed us to simulate our ZigBee network performance so that we were able to deploy with 100% confidence."
Solution
More than 650 SLCs are attached to street lights scattered across the island of St. John. Because of the ruggedness and range of Digi's XBee-PRO ZB module, CIMCON was able to establish full communication across the entire island by deploying only two gateways. The gateways then connect the mesh network to Cimcon's LightingGale management software where customers can easily access street light energy consumption data and control individual lights.
"The island only has two gateways covering 28 square miles of land," Agrawal added. "I was pleasantly surprised that the Digi modules could cover the entire island with only two gateways. The products provide tremendous range through dense brush and over mountains – and we even have some modules covering 1.7 miles over water."
Results
In addition to street lighting control, the solution enables smartphone applications where customers can set up alarms and receive notifications regarding energy consumption and faults – improving customer satisfaction and reducing energy consumption. The XBee-powered mesh network will also be used by the Virgin Island Water and Power Authority to connect its electrical monitoring reclosures. Approximately 60 reclosures are located throughout the three US Virgin Islands, transmitting power to homes and businesses. When completed, the Virgin Island Water and Power Authority will be able to easily monitor and control each reclosure remotely over the mesh network.
"Digi was extremely supportive before we were even in there with customers," Agrawal concluded. "Tech support was very helpful in the beginning in trying to determine where the load would be. We were able to simulate up to 15 hops in 500 nodes using Digi's K-Node service and established parameters that would work for the network. Once we were on the island, everything just worked like it did in the lab. We were so well prepared going in that we haven't needed any tech support since.