SeaTalk and RS125 GPS

[Chuck - Raymarine - Moderator]

Welcome to the new Raymarine Forum Paul,

Q1. I was told I could test both the SeaTalk port on the MFD and the SeaTalk output of the RS125 using an analogue multi-meter while connected via NMEA and receiving signal. The moderator said I should see the meter pulse between 6 & 11 VDC.

A1. This is not quite what you were told. Please additionally note that the Raystar 125 GPS Sensor cannot be simultaneously interfaced to both SeaTalk and to the NMEA 0183 port of a device. Should the MFD be interfaced to a NMEA 0183, SeaTalkng/NMEA 2000, or SeaTalkhs source of GPS data (verified via the MFD's GPS Status dialog), then this GPS data will be bridged by the MFD to its SeaTalk port. As such, should voltage be measured across the SeaTalk Data (yellow) and SeaTalk ground (black leads) of the MFD's SeaTalk/Alarm cable, then the meter's needle should pulse between +9 to +11 VDC (the magnitude of the pulse may vary be a volt or so), signaling data transmission. Should voltage be measured across the SeaTalk Power (red) and SeaTalk ground (black leads) of the MFD's SeaTalk/Alarm cable, then the measured voltage should be approximately 12 VDC. Should your results have been similar to what has been stated within this paragraph, then the MFD's SeaTalk port would be deemed to be operational.

Q2. I did the test the other day and I did get very discernable pulses when testing the GPS but when I tested the E120 the meter stays steady at about 11 VDC. So, my question then is does this indicate that the SeaTalk bus on my E20 has gone bad?

A2. Should your findings not be as has been specified within the first paragraph of this response, then it would appear that your MFD has suffered a failure of its SeaTalk communications circuitry.