The VL-SDN is used for the distribution of
redundant NMEA. With its 2 galvanically isolated
NMEA inputs, the module automatically choose
between the two inputs, and then forward it to
12xRS422 and 2xRS232 outputs. If the main input
does not receives any signals, the module is then
automatically switches to the second input. An
option of manual switching between 2 inputs is also

Through 2 voltage inputs, the power supply
9-32VDC is designed as a fail-safe (MSB-ESB).