Metasphere has made the SDI-12 serial communications protocol available on its battery powered remote telemetry units (RTUs). This allows them to connect to a range of intelligent sensors that are widely used in water resource research and management, industry, government, and agriculture.
It is a standard that was developed for low power data acquisition systems allowing micro-processor based sensors to communicate efficiently with low power data loggers and remote telemetry units such as the Point Green, Orange and Blue.
The SDI-12 protocol follows a master-slave configuration and provides a means for the RTU (master) to provide power and transfer measurements taken by an intelligent sensor (slave).
There are many benefits to the inclusion of the SDI-12 interface, they include the fact that unique and complex self calibration algorithms can be done in the micro-processor based sensors, that power is supplied to the sensors through the interface and that sensors can be interchanged without reprogramming the RTU. There are also increases in accuracy due to the removal of multiple analogue to digital conversions found in typical analogue sensor interfaces.