CSOnet is a modular, decentralized approach to Real Time Monitoring and Control (RTMC), which sets it apart from many existing systems.  Most existing RTMC systems utilize Programmable Logic Controllers (PLCs) to gather data from sensors mounted in the sewer.  The data is then sent to a centralized computing center via a Supervisory, Control, And Data Acquisition (SCADA) system.  This computing center analyzes the data, determines what the set points for the control valves should be using a computer model of the sewer, and then sends these set points back to the PLCs, which then move the valves.  The whole process is then started again a few minutes later.  While this system has been shown to be effective, it is also limited and cumbersome.  For example, each monitoring site requires an external power source, an electrical cabinet, a PLC, high power radios, and an open area of land for the equipment. This setup is expensive, which limits the number of monitoring sites a municipality can have, and the power and space requirements limit where the sites can be. 

      With its decentralized approach to RTMC, CSOnet avoids all of the limitations of the centralized system.  In its most basic form, CSOnet is a wireless network of monitoring points (also known as instrument nodes or INodes) and data acquisition points (also known as Gateways).  An INode collects data from a sensor mounted in the sewer and uses a radio to transmit it to a nearby Gateway.  The Gateway then uploads this data to a secure website via cellular or Wi-Fi connection, where it can be accessed anywhere at any time by the municipality.  This wireless network approach enables CSOnet to be quickly and inexpensively deployed and to be incrementally implemented, meaning the system can easily grow from one monitoring point to 10 points to 100 points.

      Rather than needing a PLC, a power source, and a SCADA system, the INode is all self-contained in EmNet's Manhole Cover.  The INode’s antenna is encased inside of the highway-rated manhole cover, which is made of a composite fiberglass material.  The necessary electronics and batteries are contained in an explosion proof enclosure mounted to the underside of the manhole cover.  An INode can be installed in any manhole in a matter of minutes and can start sending data instantly.

      The Gateway effectively replaces the centralized computing center.  The coffee-can sized node is mounted above ground, typically on a utility or traffic signal pole, so that it can collect data from surrounding INodes, which it then uploads to the Internet.  In addition to collecting data, the Gateway can be connected to, and control an actuated valve.  The Gateway contains an embedded PC, which analyzes the data collected from the surrounding INodes, and then adjusts the valve accordingly.  If more than one control point exists in a CSS, the Gateway communicates with the other Gateways via the Internet to ensure that the Gateway’s actions will cause no flooding or CSO events downstream.