[CA] Raystar125 Connection with Seatalk ng

[Redman]

I am planning upgrade my current Seatalk system which consists of C80, ST60, and autopilot (ST6001, S1, Raystar125), plus a non-Raymarine VHF. The VHF receives its GPS signal via its NMEA 0183 input connected to the S1 NMEA 0183 output.
I plan to keep the autopilot and integrate it with my new STng system via the ST to STng converter and connecting the ST6001 and S1 (no red power wire) to a D244 junction box. Two questions:
1. Do I keep the Raystar 125 ST wires connected to the S1 as its GPS source or will the autopilot get the GPS signal from my new Axiom MFD?
2. Will my VHF still receive a GPS signal from the S1 either thru the Raystar or MFD depending on answer to #1?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Redman,

General comment: Please click here to view a FAQ addressing replacement of an C-Series Classic MFD with an Axiom MFD. In this case a SeaTalk to SeaTalkng Converter will form the powered and properly terminated SeaTalkng / NMEA 2000 Backbone. Of the S1's two SeaTalk ports, one should be interfaced to the ST6001 autopilot control head and the other SeaTalk port should be connected to a SeaTalk bus which is interfaced to the SeaTalk to SeaTalkng Converter. The SeaTalk bus which interfaces the S1 Autopilot Course Computer to the SeaTalk to SeaTalkng Converter should also include the Raystar 125 GPS Sensor. When connecting this same SeaTalk bus to the S1 Autopilot Course Computer's SeaTalk port, only the cable's data (yellow) and ground (shield) leads should be connected to the SeaTalk port's terminals. The cable's red lead should be insulated to prevent shorting. The Raystar 125 GPS Sensor will receive power via the SeaTalk to SeaTalkng Converter while the ST6001 will be powered by the S1 Autopilot Course Computer's other SeaTalk port.

Q1. Do I keep the Raystar 125 ST wires connected to the S1 as its GPS source or will the autopilot get the GPS signal from my new Axiom MFD?
A1. See the General comment above. Should the Raystar 125 GPS Sensor be operational, then it would be recommended that it be retained for use by the system if it's mounting location affords it a better view of the skies overhead than is afforded the MFD. As the system features more than one device producing GPS data, the MFD's Data Sources feature will need to be used to specify which of the system's two GPS data sources will serve as the GPS data source for the entire system.

Q2. Will my VHF still receive a GPS signal from the S1 either thru the Raystar or MFD depending on answer to #1?
A2. Should the VHF radio have received GPS position data previously from the S1 Autopilot Course Computer's NMEA 0183 output port, then it may continue to do if the equipment is installed as specified within my General comment above.

[Redman]

Thank you Chuck. I've delayed my install but still planning. Follow-up questions...
Q1: The MFD GPS will have no issues w/ signal. Given this, wouldn't it be best to utilize this latest GPS technology vs. the old GPS technology in the Raystar?
Q2: If I choose not to connect the Raystar 125 and utilize Axiom MFD internal GPS, will my VHF radio still receive the GPS signal via the Seatalk/Seatalk ng backbone?

[Chuck - Raymarine - Moderator]

Redman,

Q1: The MFD GPS will have no issues w/ signal. Given this, wouldn't it be best to utilize this latest GPS technology vs. the old GPS technology in the Raystar?
A1: That depends upon whether the new MFD's installation location affords it as good or better GPS signal reception than was available to the Raystar 125 GPS Sensor. If so, then it would be recommended that the Raystar 125 GPS Sensor not be used. If not, then it would be recommended that the Raystar125 GPS Sensor or a Raystar 150 GPS Sensor be used. Maximum performance of the system should be achieved through use of a GPS sensor having a 5Hz or 10Hz update rate. The Raystar 125 GPS Sensor supports a 1Hz update rate.

Q2: If I choose not to connect the Raystar 125 and utilize Axiom MFD internal GPS, will my VHF radio still receive the GPS signal via the Seatalk/Seatalk ng backbone?
A2. Which make/model of VHF radio is installed onboard the vessel?

[Redman]

The VHF is. Standard Horizon GX1256S

[Chuck - Raymarine - Moderator]

Redman,

The Standard Horizon GX1256S only features a NMEA 0183 communications interface. As the Standard Horizon GX1256S does not feature a NMEA 2000 communications, it cannot simply be interfaced as a spur to the system's powered and properly terminated SeaTalkng / NMEA 2000 backbone. However, should the backbone include a SeaTalk to SeaTalkng Converter and its SeaTalk socket only be interface to the VHF radio as shown within the FAQ found here, then the SeaTalk to SeaTalkng converter may supply the VHF radio with GPS data from the system's SeaTalkng / NMEA 2000 backbone.

[Redman]

Thanks Chuck. Since it appears only the VHF can be connected to this converter, is it possible to have second seatalk to seatalk ng converter within the system to interface the ST6001 autopilot? If so I assume the converter would be connected via a blue backbone cable. Would both need to be powered or just one? If only one, does it matter which?

I should also ask if a device such as The Actisense NGW-1 device would be another method to connect the VHF to the backbone and receive the GPS signal from either the axiom internal GPS or the RS150.

[Chuck - Raymarine - Moderator]

Q1a. Since it appears only the VHF can be connected to this converter, is it possible to have second seatalk to seatalk ng converter within the system to interface the ST6001 autopilot?
A1a. Yes.

Q1b. If so I assume the converter would be connected via a blue backbone cable.
A1b. Correct

Q1c. Would both need to be powered or just one? If only one, does it matter which?
A1c. Only one SeaTalkng Power Cable should be interfaced to the backbone. The spur socket used should be located at the approximate midpoint of the backbone's LEN load.

Q2. I should also ask if a device such as The Actisense NGW-1 device would be another method to connect the VHF to the backbone and receive the GPS signal from either the axiom internal GPS or the RS150.
A2. Indeed use of third party NMEA 0183 to NMEA 2000 data bridging devices such as the one you have referenced is another means of achieving the same end.