[DG] [DG11] Interfacing es128 with NMEA v1.5 equipment

[Nandi]

My 'new' sailboat has B&G 'Network' instruments (wind/speed/depth/data/repeater) daisy chained with Network cables. This can output NMEA 0183 v1.5
Also have B&G 'Network' Pilot connected to the system, this also can receive NMEA 0183 v1.5
NASA AIS ENgine 3 (2017), I believe this transmits NMEA0183 HS; this is connected at present to an older standalone plotter.

I have a new es128 MFD which I would like to interface to the above so that the MFD receives/displays wind/speed/depth/heading and AIS data, and hopefully also use this to utilise the collision avoidance and layline features; and also so the MFD sends waypoint and route info to the pilot to follow when in 'NAV' mode. I realise that the autopilot control feature of the MFD will not be available.

I also have dsc vhf but this needs mmsi reprogramming so this can wait till a later date.

Could you advise the best/most cost effective way to achieve this-do I need multiplexers/converters etc., or can I do this simply using the NMEA cables combined in the es 128 power/video/NMEA cable? If so, can you advise what connections should be made.
I am a bit familiar with the single ended/differential variation of NMEa v1.5 and v2, but no expert!

[Derek - Raymarine - Moderator]

Hi Nandi,
Thank you for your enquiry.

The eS128 MFD can both output and receive NMEA0183, however, you will need to scheme the system out first to make sure that you avoid data loops and manage the combination of 4800 and 38400 baud rate NMEA correctly.

The eS128 has 2 NMEA ports, port 1 can both transmit and receive, port 2 is receive only. Both ports can be set to either 4800 or 38400, note that if you change the setting on port 1 it affects both transmit and receive of port 1.

The suggestion would be to connect the AIS to port 2 since it will likely need to be set to 38400 baud.

The B&G should be connected to port 1 both transmit and receive. A word of caution however, depending on the setup of the B&G system, you may trigger a data loop and so check you can prevent this by deselecting non-essential sentences from being transmitted by the B&G system and also you can deselect some NMEA sentences from being re-transmitted by the eS128

The below diagram will indicate connections



regards

Derek

[Nandi]

Hi Derek,

Thanks very much for your reply. Could you possibly clarify a couple of points...

The AIS connection is straightforward.

But, could you clarify connecting the B&G instruments and Pilot (All NMEA v1.5) to port 1 - connecting the B&G output NMEA would, I assume, be NMEA Tx to MFD port 1 input +ve (say, white data wire) and NMEA ground to MFD port 1 input -ve (green wire). ?
Then presumably MFD output NMEA would be port 1 output +ve (yellow wire) BUT port 1 output -ve (brown) left unconnected and the MFD main cable shield connected to B&G ground. This to avoid ground loops/current drain from MFD output -ve ?

Would using a multiplexer such as Actisense's ncd- 4- ais provide a better solution in any way ? I prefer not to add more gear if it's not necessary.

Cheers
Alan/Nandi

[Derek - Raymarine - Moderator]

Hi Alan,

As per the previous diagram we sent, white is the port 1 data input +ve and green is the port 1 data input -ve.

Yellow is port 1 data output +ve and brown is the port 1 data output -ve. You do not leave the brown disconnected. The power lead shield connection is provided for RFi protection purposes and so is only to be used for that purpose.

Thanks
Derek

[Nandi]

Thanks again Derek - much appreciated.

I guess I was a bit concerned having read the info on the Actisense website suggesting the -ve output from a differential talker (v.2) should not be connected to the equivalent connection on a single ended listener device (v1.5) as it risks damage to the talker ( my expensive es128 !).
Please see attachments showing what they say.

However I am probably missing something here so will go ahead and connect as you suggest if there is nothing else to consider. Would appreciate it if you could explain where I am going wrong in my thinking.

Cheers

Alan/Nandi

[Derek - Raymarine - Moderator]

Hi Alan,

Raymarine NMEA 0183 connections are opto isolated (as are the Actisense devices) so this should not be a problem, please just go ahead and connect as I suggested.

Thanks
Derek

[Nandi]

Hi Derek,

Thanks for that, it clarifies things for me.

Your help was much appreciated.

Cheers
Alan

[Derek - Raymarine - Moderator]

Hi Alan,
No Problem,
Pleased to help!

Best regards
Derek