NMEA 0183 Multiplexer (RS232/PC Port) (For Serial Port Connection) (For ease of installation this unit is preconfigured as an autoswitch). Autoswitch up to 4 NMEA inputs to your PC, Chart-plotter, Radar, Autopilot and more, with NMEA 0183 HS compatibility and ISO-Drive. This Actisense™ NMEA Multiplexer / Combiner allows connection of up to five NMEA (National Marine Electronics Association) inputs, and multiplexes / combines or autoswitches them to its two fully isolated NMEA outputs. This approach offers these major advantages: Completely removes the need for isolated power supplies - as the NDC-4 creates a full 2500v isolation barrier between it's inputs and each of it's ISO-Drive outputs.

Enables the vessel owner complete access to all NMEA data sources, instead of the standard one device. Any problematic or unwanted NMEA sentences can be filtered out / blocked, to help intelligently reduce the NMEA data to a manageable amount and prevent data loops. Each NMEA input device is Opto-isolated from all other NMEA device in the system. Significant reductions in installation cost (from reduced cable lengths and requiring only one NMEA cable to be routed around the bridge to supply the multiplexed NMEA data.

If the NMEA data from two (or more) devices are simply combined together, the NMEA listener(s) will not be able to differentiate between the various sources and will get very confused, often jumping between them. If this creates a ‘jumping’ position fix, vessel safety is seriously affected. The NDC-4 Autoswitch mode is the perfect solution to this problem - automatically selecting a single device from the multiple ‘same data type’ devices available. Autoswitch mode will automatically select the highest priority device from up to 4 connected input devices, with NMEA port 1 as the highest priority through to NMEA port 4 as the lowest.