Inductive Mooring Line Modem MLM-1000
RBR's inductive modem communication system, the MLM-1000, for XR and XRX series CTD (conductivity, temperature and depth) loggers (sonde, recorder), for the DBC2 and for OEM applications is designed to provide fast communication with loggers deployed up to a kilometre in depth. The modem uses an underwater transformer to transmit information through a jacketed mooring line without requiring cables or connectors. Essentially an unlimited number of instruments may be connected to the MLM-1000 and communication at 4800 baud is provided over an insulated mooring line of up to 1,000m length. Features include transparent link and automatic node discovery. CRC error detection is included. The MLM-1000 can drive RF, cellular, or satellite telemetry directly.The conductor loop is comprised of the steel core of a jacketed mooring cable and sea or fresh water. The ends of the steel cable are stripped of the insulating jacket and are thus in contact with the water. Between the stripped ends of the cable, the water provides a conduction path for electric current. Each system node typically uses a toroidal transformer that is clamped around the mooring line. The magnetic coupling between the toroid and the mooring cable is the medium by which nformation is transferred between the mooring cable and the particular system node.
- The ability to receive oceanographic measurement data from any one of a network of deployed RBR logger instruments in "near real-time".
- The ability to alter sampling regimes for already deployed logger instruments, for example in response to changing marine environmental conditions.
- The ability to gauge the status and functional health of deployed instruments.
- The ability to download data from logger instrument memory while the instrument is deployed.