GPS RS125 NEMA or Sea Talk

[ahalpern]

I am using a Raymarine Pathfinder system, 2-RL70CRC+, DM250 sonar, 4K Radar, S2 course computer, ST6001 controller type 2 drive auto pilot (2 control heads), Flux gate compass, Rudder indicator, RN300, E35009 Antenna. The system is wired to Seatalk and NEMA 183.

I have been having problems with the RN300 locking up and needing a power off reset to establish a Fix. When a friend offered me a RS125 GPS after he updated his system I was anxious to replace the RN300. After removal of the RN300 I connected the RS125 to the Seatalk bus. The LED on top went from red to yellow and then green, blinking very close to 4 seconds. The problem is the 2 MFD’s indicate “No Fix”.

My questions are, 1. If the RS125 shows the indicator lights does that mean it’s working? 2. Should I have connected the RS125 to the NEMA bus instead of Seatalk? 3. I understand that the Raystar 125 GPS Sensor cannot be simultaneously interfaced to both Seatalk and to the NMEA 0183 port of a device, if it were then this GPS data will be bridged by the MFD to its SeaTalk port true or false?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Technical Forum ahalpern,

Q1. If the RS125 shows the indicator lights does that mean it’s working?

A1. As you can see from the information below regarding the RS125's Status LED, the RS125 has acquired a GPS position FIX and is transmitting data via SeaTalk communications protocol.



It is recommended that you verify that the GPS sensor has been interfaced to the SeaTalk bus per the attached chart, with specific focus on the RS125's yellow lead. Should you have done so and the problem persists, then it would appear that the RS125 has suffered a failure of its SeaTalk communications circuitry and it would instead be recommended that it be interfaced via NMEA 0183 to one of the displays (see attached chart).

Q2. Should I have connected the RS125 to the NEMA bus instead of Seatalk?
A2. This option would only typically be recommended only when a problem had been detected with the SeaTalk communication circuitry of the RS125 or one of the devices within the system, or if seeking to supply a device with GPS data when only the RS125 is powered.

Q3. I understand that the Raystar 125 GPS Sensor cannot be simultaneously interfaced to both Seatalk and to the NMEA 0183 port of a device, if it were then this GPS data will be bridged by the MFD to its SeaTalk port true or false?
A3. If the RS125 was interfaced to the one of the Pathfinder display's via NMEA 0183 instead of to the SeaTalk bus, then the Pathfinder display would bridg received NMEA 0183 GPS data to SeaTalk for use by the rest of the system.