OTT HydroSystems offer a decisive price advantage compared to individual configured systems. The IP-enabled and highly energy-efficient datalogger OTT netDL is the core of the system. Several SDI-12 sensors may be connected to the rugged logger, as it has up to 40 channels. The measured data may be remotely transferred via the built-in cellular modem, optionally via satellite or Ethernet. The required antennas are already included in the system.