Log Pulse NMEA Converter

SLNC-20 Log Pulse to NMEA Converter

The Log Pulse NMEA Converter interface converts, incoming speed data as contact closure data to NMEA format.

Old speedlog devices, speed data is sent to other devices according to a contact closure signal.
On some older marine bridge navigation devices, speed data was accepted based on a contact closure signal. SLNC-20 converts the contact closure signal to the NMEA format. It can be used especially for old autopilots, gyrocompass, ODME systems. A converter is required as newer devices do not have this interface.

A vessel with an older mechanical log that produces pulses proportional to speed can use an NMEA log pulse converter to integrate this speed data into a modern chart plotter. The converter reads the pulses, processes them, and outputs an NMEA 0183 sentence like $VHW,12.5,T,10.0,M,5.5,N,2.8,K*hh, where “12.5” and “10.0” represent speed through the water in knots and meters per second, respectively.

The converter has two RS422 NMEA outputs. The output speed can be adjusted with DIP switches. Configurable log pulse input with DIP Swithces.

By understanding and implementing an NMEA log pulse to NMEA 0183 converter, marine vessels can achieve improved data integration, enhance navigation accuracy, and effectively utilize legacy speed sensors with modern navigation systems.

The SLNC-20 can be powered within the range of 9~32 VDC. The nominal voltage of 24 VDC is advised for powering the device in normal operation. Power input port has a protection for incorrect polarity connection of the supplying voltage.