Water and Sewage Monitoring
Ensure efficiency with Water and Wastewater Monitoring: advanced IoT solutions for real-time control, analysis, and management of sanitation.
Challenge
To remotely communicate with PLCs (Programmable Logic Controllers) located in various units of the water and sewage system of a large Brazilian city.
Solution
Multiplexing of Serial PLCs over the Internet via a virtual Serial channel.
The client's requirement was to perform control and telemetry of various points in the water and sewage system of a large Brazilian city. The high cost of acquiring and maintaining dedicated lines (LPs) made performing these tasks reliably and continuously extremely expensive. The Operational Control Center, located at the client's headquarters, needed constant communication with the PLCs located at these points.
Project requirements:
- Reliable and stable communication with PLCs scattered throughout the city, many in hard-to-reach areas;
- Affordable solution cost;
- The device can be connected via Ethernet or Serial, allowing for standardization and integration with various PLC models.
Several technologies were tested, and each demonstrated weaknesses, such as low robustness or communication instability. For example, LPs frequently had their wires stolen. Wireless communication solutions were impractical due to line-of-sight and distance issues. Satellite communication, in turn, had a very high operating cost.
In addition to these difficulties, there was another complicating factor: the multiplexing of serial networks for PLC communication via the cellular network. Among several competitors, Above-Net was the only one capable of overcoming this barrier and delivering a reliable, highly available solution with excellent cost-benefit.
The solution consists of a 3G router connected to the PLC, which in turn connects to various devices at the workstations. The router remains permanently connected to the Bridgemanager cellular connection management system and is able to inform the supervisory system of the access path of each device connected to the PLC. In this way, the client can monitor various devices securely and reliably through a single cellular connection.