Providing an ICOM VHF radio and/or SSB with GPS data from a Raymarine system

[Chuck - Raymarine - Moderator]

Providing an ICOM VHF radio and/or ICOM SSB with GPS data from a Raymarine system

The function of a NMEA 0183 Talker ID is to identify the source of data contained within the NMEA 0183 sentence being transmitted. Should your Raymarine system feature and be configured to use an external GPS sensor (ex. Raystar 130 GPS) as its GPS data source, then the MFD will correspondingly transmit NMEA 0183 GPS sentences featuring the "EC" (Electronic Chart Display & Information System) NMEA 0183 Talker ID instead of the "GP" NMEA 0183 Talker ID, as the MFD is not the source of the GPS data for the system. However, should your Raymarine MFD feature an internal GPS receiver and the Raymarine system be configured to use the MFD's internal GPS receiver as its GPS data source, then the MFD will correspondingly transmit NMEA 0183 GPS sentences featuring the "GP" (Global Positioning System) NMEA 0183 Talker ID instead of the "EC" NMEA 0183 Talker ID, as the MFD is the source of the GPS data for the system.

Unlike most VHF radios some ICOM VHF radio and SSB products will ignore 4800 BAUD NMEA 0183 sentences which include a NMEA 0183 Talker ID other than "GP". It is recommended that customers consult the third party VHF radio's / SSB's owner's manual or contact the VHF radio manufacturer if uncertain of the VHF radio's NMEA 0183 sentence requirements. Should your VHF radio have this requirement, then a SeaTalk to SeaTalkng Converter (updated with v1.21 or later SeaTalk to SeaTalkng Converter software) may be used to supply 4800 BAUD NMEA 0183 GPS data from the Raymarine system to the VHF radio to support it DSC functions.

Raymarine introduced a feature within the v1.21 SeaTalk to SeaTalkng Converter software update permitting a SeaTalk to SeaTalkng Converter to transmit a limited set of 4800 BAUD NMEA 0183 GPS sentences. Following the software update, the SeaTalk to SeaTalkng Converter will be operate "sense mode" for the first twenty seconds after being powered. If first generation SeaTalk communications packets are detected while in Sense Mode, then the SeaTalk to SeaTalk Converter will operate as a SeaTalk to SeaTalkng data bridge. However, if no first generation SeaTalk communications packets are detected while in Sense Mode, then the SeaTalk to SeaTalk Converter will instead transmit the following 4800 BAUD NMEA 0183 v4.10 sentences featuring the "GP" NMEA 0183 Talker ID:

GGA - If L/L is present on STng, then GGA will Tx only populating data fields that are available, i.e. time/date etc.
RMC - If L/L is present then RMC will Tx only populating data fields that are available, i.e. time/date etc.
VTG - If SOG and/or COG valid in 129026 then VTG will Tx only populating data fields that are available, i.e. variation etc.



RAYFAQ#