[CA] [CA11] RS125 - No communication

[Zulu]

The GPS receiver was working fine but i noticed it started taking longer to get a fix until it stopped working. The GPS status screen on the Raymarine E120 MFD displays no data.
I changed the battery in the RS125 unit but still no data.
I then found the thread "RS125 - NO FIX being reported on Pathfinder Series Display or Multifunction Display" on this forum and measured the voltage between the different pins as prescribed.

The results are as follows:
----- Between pin 1 (red) and 2 (black or shield): +11.9VDC
----- Between pin 1 (red) and 3 (yellow): fluctuates between 0 and 3.8 VDC
----- Between pin 5 (green) and 2 (black or shield): +11.9VDC
----- Between pin 4 (brown) and 2 (black or shield): No voltage

The white cable in the attached photo is the one coming from the RS125. Pins 4 and 2 are connected together so that explains the 0 voltage. It seems like the problem is between pins 1 and 3. Is there a common cause for this?


Regards

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Zulu,

Your description and photograph of the wiring connections indicate that the RS125 has been interfaced in a manner which would support SeaTalk communications with the SeaTalk bus. As indicated within the FAQ which you have referenced, if the sensor is located where it has and unobstructed view of the skies overhead, then the symptoms which you have reported are indicative of a depleted battery within the RS125 or a failing GPS sensor. Please refer to the directions within the referenced FAQ to replace the RS125's battery.

[Zulu]

I have already replaced the battery and the sensor has an unobstructed view. Attached is a photo of the MFD screen for GPS status

[Chuck - Raymarine - Moderator]

Zulu,

Please accept my apology for having missed that you had already replaced the sensor's battery. No communications appear to be occurring at all between the GPS sensor and the MFD. Additionally, the measured voltages are outside of those with the referenced FAQ. Based upon the information supplied, it would unfortunately appear that at a minimum, the SeaTalk communications circuitry of the GPS sensor has failed. It is recommended that it be replaced with a Raystar 150 GPS Sensor as shown within the FAQ found here. Alternatively and should the MFD's NMEA 0183 port not be in use, then the GPS sensor may be replaced by a GPS sensor supporting 4800 BAUD NMEA 0183 communications (ex. Tack Tick T908 GPS Sensor, etc.).

[Zulu]

I have done some more fault finding but first let me try to explain the system. At the helm station I have a E120 Classic MFD a i70, ST60+and ST6002. The i70 is connected with Seatalkng through a iTC5 and the ST60+ is connected to Seatalkng. See photo attached.

The navigation station has the following instruments. E120 classic MFD (Set as data master) a St60+ a ST70 and a Smart controller (A18105) for the autopilot.

I found that when I switch the E120 at the helmstation off that the GPS works fine most of the time.

I checked the software versions for both the E120 MFD's and found that the one at the navigation station (Data master) is v5.52. The one at the helm station is v5.69. I have no idea why the previous owners did not upgrade both. I also sometimes get a "No data master set" message at the helmstation.

I guess the starting point would be to upgrade both to the latest version. Is it 5.69 and will all else still work fine if I upgrade both.

Regards

[Chuck - Raymarine - Moderator]

Zulu,

Q1. I found that when I switch the E120 at the helmstation off that the GPS works fine most of the time.
A1. With the MFD switched OFF, check the i70/i70S MFID to determine whether it is populating data cells which have been configured to display the lat & long data items. If so and as the system features a powered and properly terminated SeaTalkng / NMEA 2000 backbone, care must be taken to ensure that SeaTalk bus is only being powered by the backbone via the SeaTalk to SeaTalkng Converter. Accordingly, only the Alarm leads of the SeaTalk/Alarm Cable should be used. Instead, the Data Master MFD's SeaTalk/NMEA 2000 port to a spur socket within the backbone via an A06061 / 4.92in (1.5m) E-Series to SeaTalkng Adaptor Cable to permit the MFD to access data previously accessed directly from the SeaTalk bus. Please additionally ensure that the MFD has been updated with E-Series Classic MFD v5.69 software.

Similarly, care should be exercised with how the autopilot course computer has been interfaced to the system to ensure that it is not supplying power to any device other than an autopilot control head and/ or wireless autopilot base station. Please click here to view a FAQ addressing this subject.

Q2. I guess the starting point would be to upgrade both to the latest version. Is it 5.69 and will all else still work fine if I upgrade both.
A2. I would agree that this is indeed necessary for the following two reasons:

- for proper operation of the system, the software for the E-Series Classic MFDs was exclusively designed and tested to support a system in which all MFDs were operating with the same software level.

- the devices which you have listed / shown include a powered and properly terminated SeaTalkng / NMEA 2000 backbone. Should the MFD's NMEA 2000 port be used to interface the Data Master MFD to the system (considered to be a best installation practice and advised above) instead of its SeaTalk communications interface, then the MFDs must be updated with E-Series Classic v5.69 software.

[Zulu]

Good day

Some more fault finding results.

This morning the GPS did not connect. The battery bank was at 84% (12.6V). With the Helmstation MFD switched off I then started the engines and the GPS immediately connected. I switched the engines off and it stayed connected.

I only ran the engines for about 1 minute. I then switched the Helmstation MFD on and the GPS disconnected. I switched Helmstation MFD off again and re booted the system and no GPS connection. I then started engines and the GPS connected again. Switched Helmstation MFD on with engines running and GPS stayed connected.

Does this confirm that the GPS unit is faulty and needs to be raplaced?

[Chuck - Raymarine - Moderator]

Zulu,

Q. Does this confirm that the GPS unit is faulty and needs to be raplaced?
A. I do not believe that this is the case. I believe that there may be an issue with the manner in which the SeaTalk bus is being powered, resulting in an insufficiently powered SeaTalk bus or possibly a ground loop. It is recommended that you ensure that
- the MFD(s) have been updated with E-Series Classic MFD v5.69 software,
- the SeaTalk bus is only being powered from a switched 12VDC power circuit, that the MFD's SeaTalk / Alarm Cable not be used for anything other than connecting the systme to an external alarm (i.e. sever the cable's rec, yellow, and black leads if currently in use),
- that the MFD be interfaced to the system via the aforementioned A06061 / 4.92in (1.5m) E-Series to SeaTalkng Adaptor Cable,
- that the SeaTalkng Power Cable has been connected to a switched 12VDC power circuit,
- that the SeaTalk connections to the autopilot be inspected to ensure that one of the autopilot's SeaTalk port has been dedicated to interfacing and powering the autopilot control head(s) and wireless autopilot base station alone, and
- that the remaining SeaTalk connection to the autopilot's course computer ... which eventually connects the autopilot course computer and any SeaTalk devices (instruments, Raystar 125, etc.) to the SeaTalk to SeaTalkng Converter is not utilizing the red terminal of the autopilot course computer's SeaTalk port. The red lead of this SeaTalk Cable will not be used and should be insulated to prevent shorting.

Should the problem persist after having addressed the item specified within this response and my prior response, then please attach a system diagram identifying each marine electronics device within the system, how each device has been interfaced to the system, and how it is being powered.

[Zulu]

Chuck,

I found that the red lead from the Seatalk bus is spliced into the power cable for the E series classic MFD and not into the Seatalk port cable of the E series classic MFD. Is that ok or should it be powered by a separate switched 12VDC power circuit?

Regards

[Chuck - Raymarine - Moderator]

Zulu,

Q. Is that ok or should it be powered by a separate switched 12VDC power circuit?
A. This would not be considered to be a best installation practice, as it will not permit the power state of the SeaTalkng / NMEA 2000 backbone ... and therefore the SeaTalk bus ... to be controlled independently from that of the MFD. Please refer to the items specified within my last response. Should these have been addressed andshould the problem persist, then please attach a system diagram identifying each marine electronics device within the system, how each device has been interfaced to the system, and how it is being powered.