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How can an NMEA Data Multiplexer reduce the congestion on my NMEA network?

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The Actisense NDC-4 and NDC-5 have many useful features, among which is the ability to prioritise their input ports. The usefulness of this feature becomes apparent when the NMEA network is running over 50% loading/capacity (most setups). At this point a standard NMEA Multiplexer could start to delay the important information by an unacceptable amount and may even lose it altogether.

The Actisense NDC however, will always transfer the highest priority input’s NMEA sentences first, keeping the delay to the minimum possible. The remainder of the inputs will have their NMEA sentences transferred in turn, until all data is either transferred or no more time / bandwidth is available in the NMEA output.

For example, the most relied upon unit e.g. GPS, should be attached to input port 1 (the highest priority).

The Actisense NDC-5 defaults follow the logical port numbering, i.e. port 1 is the highest priority. These priorities can be re-configured as required by using the NDC Control Centre PC software for an NDC-4, or via the web page config for an NDC-5. – please view the downloads page to get your copy of the NDC Control Centre for NDC-4.

For more information on NMEA 0183 and how it works, please download our free guide to NMEA 0183 networking here: https://actisense.com/everything-to-know-about-nmea-0183-guide/
For more information on NMEA 2000 and how it works, please download our free guide to NMEA 2000 networking here: https://actisense.com/complete-guide-to-building-an-nmea-2000-network/