NMEA 2000

[David2452]

It is not allowed in the NMEA 2000 standard.

I assume you are also an NMEA member and like me have access to the standards documentation, always ready to learn and as I can't find a specific exclusion of it, can you PM me, or just quote the passage reference number.

 

[knuterikt]

The PGNs in N2K should mean the end of all that nonsense.

Are you sure? I just checked the PNG's for the GWS 10, no mention of calibration PNG's there.

I was under the impression that NMEA 2000 are missing two things..
-A standard for calibration of sensors
-A standard for updating software on devices

I have Raymarinn i70 instruments but no Raymarine MFD so I have take the instruments of the boat to get updates...

 

[knuterikt]

That is not a drop cable, its simply a connection and is a part of the node, in the diagram its not described as such and should never be. A drop cable is a cable Teed off the backbone leading to a node, either thick or thin N2K cable not exceeding 6m (the reason for having masthead devices and often rudder transducers at the end of the backbone). Also, forgot to mention, for the OP, try to get the power insertion Tee as close to the masthead end of the backbone as possible to avoid voltage drop, you can plan and verify this with the N2K design software which is free on the Maretron site and saves a lot of time, also you can print a schematic for the network from it to keep aboard.

From Garmin documentation

 

[knuterikt]

I assume you are also an NMEA member and like me have access to the standards documentation, always ready to learn and as I can't find a specific exclusion of it, can you PM me, or just quote the passage reference number.

No not an NMEA member only an amateur relying on open sources.

Read this article here - some stuff about terminators built into the device
http://www.panbo.com/archives/2010/11/furuno_ws200_detail_youll_laugh_youll_cry.html

 

[Norman_E]

Will this Work?

Still thinking about trying to keep my VDO wind masthead units I have found that the only NMEA 0183 sentence that the VDO wind instrument puts out that can be translated to NMEA 2000 by the Actisense NGW1 Gateway is VWR, which is relative (i.e. apparent) wind speed and direction.

Am I right in thinking that if I keep the VDO wind instrument and connect its NMEA0183 output to the gateway the instruments themselves will calculate the true wind speed and direction from that plus the inputs from the log and/or GPS? Does it work that way, or is the calculation of true wind data performed within NMEA 2000 mast head units rather than in the display instruments?

 

[David2452]

From Garmin documentation

That's Just a Garmin instruction designed for easy DIY install on a small boat with a few nodes and it will work like that (probably) but I am talking about N2K standards that will certainly work on all occasions even at the limit, not just a boat with a few bits of kit.

 

[Norman_E]

I posted this once, or so I thought, and it vanished, so here goes again.

The Maretron software for designing NMEA 2000 systems is great. This is my first real attempt. You can even add pictures as I have, to show non Maretron equipment.
This diagram shows a system to use the data from my old wind system via an NMEA 0183 to NMEA 2000 gateway.

 

[Norman_E]

Still thinking about trying to keep my VDO wind masthead units I have found that the only NMEA 0183 sentence that the VDO wind instrument puts out that can be translated to NMEA 2000 by the Actisense NGW1 Gateway is VWR, which is relative (i.e. apparent) wind speed and direction.

Am I right in thinking that if I keep the VDO wind instrument and connect its NMEA0183 output to the gateway the instruments themselves will calculate the true wind speed and direction from that plus the inputs from the log and/or GPS? Does it work that way, or is the calculation of true wind data performed within NMEA 2000 mast head units rather than in the display instruments?

I asked B*G the above question and had this reply: The Triton instrument system is based on the NMEA 2000 system and as such will be expecting all data via this means, so in the price list you find information regarding sensors of this type. There are as you correctly suggested NMEA0183 to N2K gateways available to allow the input of data 0183 form, we know this works fine for such data as GPS and waypoint data, but cannot guarantee that this would work for the Wind and Boat speed functions supplied via the VDO system. We have in the setup of the Triton the ability to set SOG instead of STW for use for True wind speed and angle.

I take this to mean we haven't tried it!