Insu Loop monitoring system (GSM/GPRS) is our latest product specially developed for energy saving in conventional street light systems. By using this controller you can save up to 41 % energy by reducing the power at midnight (Considering 50 % reducing time). The specialty of power saving mode is uniform lighting thought street lighting which save power and yet avoid dark spots on road. Day light power saving scheme can also save some more energy. Apart from energy saving this can also save manpower, operating cost and can reduce manual-operating errors. This controller has Astronomical program to operate on longitude & latitude base for the whole year, by generating sunrise and sunset timings. Sunrise and sunset time changes on day to day basis and in one month there is a time change of about 30 minutes. For entire year sunrise and sunset time changes by about 190 minutes. With these much change of time a conventional timer will not serve the purpose. It can save energy up to 8 % against conventional manual operation, Photo sensors or conventional timers. Our controller incorporates a real time clock with in built battery backup for minimum 8 years. There is no need to reprogram the controller even if supply fails for long duration. Energy savings combined with reduced maintenance costs are prime benefits of street light control and management. SCADA software named City light is based on advanced use of global technologies such as GSM & real time embedded systems.