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Olly75 · 11-08-2018, 11:59

Having bought the wrong Actisense module to run all my nav through OpenCPN (the unit is now for sale if anyone is interested) I would like to confirm which is the correct one before repurchasing.

Currently my whole nav system, including the AIS, is producing NMEA2000. As I understand it the Actisense NGW-1 will convert all of this to NMEA0183 and Opencpn should be able to read it.

Is this correct?

Many thanks.

smac999 · 11-08-2018, 20:08

you would probably be better off getting an n2k to usb. or better n2k to wifi. then you wan't have a cable to the computer.

n2k to 183 may not get all the info. you'd probably have to buy the low speed and high speed one and have 2. to get all the sentances. the AIS version only does AIS sentances and the low speed version is not going to do ais. normally it goes from 183 to nmea 2000, so you'd have to confirm you get data going from n2k to 183. the AIS one does.

teppokurki · 12-08-2018, 12:14

Quote:

Originally Posted by Olly75

Currently my whole nav system, including the AIS, is producing NMEA2000. As I understand it the Actisense NGW-1 will convert all of this to NMEA0183 and Opencpn should be able to read it.

As mentioned a conversion to NMEA0183 will not get you everything, because there are no NMEA0183 messages for many NMEA2000 PGNs.

Is OpenPlotter something you might consider? In Addition to OpenCPN it includes Signal K server (among other things).

With Actisense NGT-1 and OpenPlotter you would get all common (non proprietary) NMEA2000 data converted to Signal K format, which the server can convert over to NMEA0183 and route it to OpenCPN.

Most of the ordinary stuff works out of the box, but if the setup does convert everything the way you want you can alter the way things work.

There are multiple ways to go about it: as the system is open source you can alter the code to make it work the way you want - or you can add new conversions to the system. OpenPlotter include Node-red: a graphical programming environment, where you can create new outputs from incoming data. As you would have access to all your input data you could generate essentially whatever output you want.

If this sounds complicated there is help available here and on OpenPlotter forum.

But as I said the common stuff works out of the box.

**Dockhead** · 12-08-2018, 13:24

Quote:

Originally Posted by smac999

you would probably be better off getting an n2k to usb. or better n2k to wifi. then you wan't have a cable to the computer.

n2k to 183 may not get all the info. you'd probably have to buy the low speed and high speed one and have 2. to get all the sentances. the AIS version only does AIS sentances and the low speed version is not going to do ais. normally it goes from 183 to nmea 2000, so you'd have to confirm you get data going from n2k to 183. the AIS one does.

OpenCPN, like virtually every other nav software program, only speaks 0183, so this is not correct advice. The OP must have the data in 0183 format in order for O to read it.

And so the OP is correct -- he needs the NGW. I made precisely the same mistake 5 years ago and I still have my unused NGT in a drawer some place. I'll get around to using it for something, some day.

As an alternative to an NGW, he can hook up to the 0183 talker port on his plotter, which is no doubt not used for anything. I did this for a while myself and it works fine. You just need an RS422-to-USB adapter which is very cheap.

Then if you have some device on the network which puts data over wifi, you can use that. I used a Go Free device for that for a long time.

Or with Navico systems with Go Free you can also connect by Ethernet. The Go Free device has an extra Ethernet port you can hook up to with the (expensive) adapter. I'm doing that now in order to get radar data into the OpenCPN radar plug-in, besides the network data.

Possibly you can connect using Ethernet even without the GoFree module. Probably. If one of your plotters has a free port, or if you have the Ethernet switch which is required in some installations.

Olly75 · 12-08-2018, 14:06

Thanks all for the info. I think on balance I will go with the NGW and see how much data I can get through it. If this doesn't work I will use Dockheads hack and connect the plotter directly to the laptop as an interim measure.

I've been looking at open plotter and raspberry pi but to be honest being a luddite its a little complicated to me. I have, however, just seen the ikommunicate signal k box. This seems to convert all data to signal k and then transmit it over wif or ethernet in HTML5.

I cant find anything in the opencpn manuals about HTML5, so can opencpn use data in this format? if so this looks like a neat (and easy!) solution.

teppokurki · 12-08-2018, 14:33

Quote:

Originally Posted by Olly75

I've been looking at open plotter and raspberry pi but to be honest being a luddite its a little complicated to me. I have, however, just seen the ikommunicate signal k box. This seems to convert all data to signal k and then transmit it over wif or ethernet in HTML5.

I cant find anything in the opencpn manuals about HTML5, so can opencpn use data in this format? if so this looks like a neat (and easy!) solution.

An OpenCPN using luddite - isn’t that a contradiction in terms?

HTML5 is web pages/apps and won’t help you get your data into OpenCPN, that accepts only NMEA0183. iK does convert some N2K to NMEA0183 though, but its coverage is fairly limited, see http://ikommunicate.com/wp-content/u...-V1_01_Eng.pdf

**Dockhead** · 12-08-2018, 15:17

Quote:

Originally Posted by teppokurki

An OpenCPN using luddite - isn’t that a contradiction in terms?

HTML5 is web pages/apps and won’t help you get your data into OpenCPN, that accepts only NMEA0183. iK does convert some N2K to NMEA0183 though, but its coverage is fairly limited, see http://ikommunicate.com/wp-content/u...-V1_01_Eng.pdf

Which leaves the question -- what N2K data do you really need, which you can't get on 0183?

I love N2K, but not necessarily because of the expanded set of sentences. All the important stuff is handled quite well in 0183, and everything -- by definition -- which OpenCPN can use.

Olly75 · 12-08-2018, 17:28

Quote:

Originally Posted by teppokurki

An OpenCPN using luddite - isn’t that a contradiction in terms?

HTML5 is web pages/apps and won’t help you get your data into OpenCPN, that accepts only NMEA0183. iK does convert some N2K to NMEA0183 though, but its coverage is fairly limited, see http://ikommunicate.com/wp-content/u...-V1_01_Eng.pdf

Thank you for the pdf. I had a read through and the list of N2000 conversions seems to cover everything that I need, so will go ahead and get one.