e125 - VHF DSC Intergration via Seatalk

[MattDonovan]

Hi,

I am trying to integrate my new Standard Horizon Matrix GX2000 with my e125 MFD.

The Chartplotter is at the helm station and is linked to my existing Seatalk 1 network via a seatalk to seatalk ng converter also at the helm (with ST60+ wind instrument, St60+ Tridata and ST6002 smart pilot controller (Smart Pilot is in the Engine Room).

The VHF will be located at the nav station inside the boat. At this station, I have an ST60+ Graphic Display, an E85001 Seatalk/RS232/NMEA interface, a Lifetag System on the Seatalk linked to the Helm. The calble channel between the 2 is about 7m.

I was planning to link the VHF NMEA0183 input and output to the E85001 interface to save running a dedicated NMEA cable to the e125, but looking through its manual, it does not appear to support the DSC/DSE sentences for DSC polling. So I don't think this is an option, is that correct?

Next I thought of using the NMEA input & output on the ST60+ Graphic display near the VHF again to save running a dedicated cable. However I read on another thread that the Seatalk to Seatalk ng Converter is not designed to handle DSC/DSE polling, so I am thinking that this will not work to get the communication between the MFD & the VHF either. Is that correct?

Which leave me my last option which is to wire the NMEA inputs outputs directly to the e125 4800 baud port1. Howver reading my manual, the maximum distance to extend the NMEA port cables is 5m and my cable runs will be in the order of 7m. Will this still work? If not are there any other options?

Thanks for your help

Matt

[Chuck - Raymarine - Moderator]

Matt,

Q1. I was planning to link the VHF NMEA0183 input and output to the E85001 interface to save running a dedicated NMEA cable to the e125, but looking through its manual, it does not appear to support the DSC/DSE sentences for DSC polling. So I don't think this is an option, is that correct?
A1. You are indeed correct in your belief that the E85001 PC/SeaTalk/NMEA 0183 does NOT support bridging of DSC & DSE NMEA 0183 sentences. Should the VHF radio not additionally be an AIS receiver, then it would be recommended that the VHF radio be interfaced directly to the NMEA 0183 leads of the MFD's Power/NMEA 0183/Video Input Cable. However, should the VHF radio additionally be an AIS receiver, then it would typically be recommended that the VHF radio/AIS receiver be interface to the MFD via a SeaTalkng/NMEA 2000 backbone to support any future expansion of the system. Should this not be a concern (Note: MFDs will not bridge AIS data received from a NMEA 0183 source to SeaTalkng/NMEA 2000), then it would be recommended that the VHF radio/AIS receiver be interface to the MFD via direct NMEA 0183 communications.

Q2. Next I thought of using the NMEA input & output on the ST60+ Graphic display near the VHF again to save running a dedicated cable. However I read on another thread that the Seatalk to Seatalk ng Converter is not designed to handle DSC/DSE polling, so I am thinking that this will not work to get the communication between the MFD & the VHF either. Is that correct?
A2. You are indeed correct in your belief that the ST60 Graphic does NOT support bridging of DSC & DSE NMEA 0183 sentences.

Q3. Which leave me my last option which is to wire the NMEA inputs outputs directly to the e125 4800 baud port1. Howver reading my manual, the maximum distance to extend the NMEA port cables is 5m and my cable runs will be in the order of 7m. Will this still work? If not are there any other options?
A3. Per the NMEA 0183 INSTALLATION AND OPERATING GUIDELINES, "Interface cables shall be kept as short as possible and shall not exceed 150 feet" ... for NMEA 0183 ports utilizing RS-422 communications. The NMEA 0183 ports of a/c/e/eS/gS-Series MFDs utilize single ended RS-232 communications, which is typically limits cable lengths to 5m, particularly if used for 38400 BAUD data rate. As you will not be extending significantly longer and the port will be configured for 4800 BAUD communications, you will likely find that extending the cable using marine grade twisted pair signal cable to 7m will work satisfactorily. If not, then it would be necessary to install a NMEA 0183 expander/RS422 converter to communications over the required distance.

[MattDonovan]

Thanks Chuck, that will make my life easier.
By the way I am not even going to tell you what the original installer connected my Smart Pilot NMEA out to my original VHF 240, but it wasn't marine grade, it wasn't twisted but you could have run a household appliance on it
Cheers
Matt

[Chuck - Raymarine - Moderator]

You're welcome.

[MattDonovan]

Chuck,
the RS232 /422 is an eye opener.

I am going to try the 7m cable for the 4800. If it doesn't work is there an NMEA expander in the Raymarine product line or is there one that you recommend?

Also, I imagine both the input and output would need to be "boosted" for want of a better term, so does that mean I need an expander on the output at both the radio and the MFD.

If the VHF is using RS-422 do I need a converter for the MFD to be able to read this and for the VHF to read the output from the MFD?

Thanks

Matt

[Chuck - Raymarine - Moderator]

Matt,

Based 14 years with Raymarine product installation, including those on my own boats, I doubt that you will need a NMEA 0183 expander for this application. Think of the function of a NMEA 0183 expander as an amplifier/signal booster. Raymarine does not offer a NMEA 0183 expander, but they are available from third parties such as Noland, Dutec, etc. Such expansion would only be applied to the NMEA 0183 talker leads. Should the VHF radio support RS-422, then no expander would potentially be required for the distance specified. Again, I have seen very few applications throughout the years which required a NMEA 0183 expander.

[MattDonovan]

Thanks Chuck,

Will try without the expander and will repost when I have success. Still cruising in the Bahamas so may be a month or so before project is completed.

Matt

[Chuck - Raymarine - Moderator]

You're welcome.

[MattDonovan]

Chuck,

just thought of another question. Planning on using shielded wire as per the manual. Should the shielding be connected to the RF Ground at the e125 MFD

Matt

[Chuck - Raymarine - Moderator]

Matt,

Please click here to view a FAQ addressing drains & RF shields.