IEC 61162-450 support

Discussion and support for the Nmea4Wifi multiplexer - a 4-input Nmea 0183 wifi multiplexer.
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rodion
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Joined: Thu Jun 18, 2020 2:04 pm

IEC 61162-450 support

Post by rodion » Thu Jun 18, 2020 5:25 pm

Hello

I wonder if Nmea4Wifi can be configured to work with IEC 61162-450 (NMEA over Ethernet) that seems to be just a multicast UDP?

Thanks
Rodion

Luis Sa
Site Admin
Posts: 843
Joined: Thu May 04, 2017 4:12 am

Re: IEC 61162-450 support

Post by Luis Sa » Thu Jun 18, 2020 5:55 pm

Hello Rodion,

I must confess that I do not know the standard you are referring to. I may try to learn it or you could describe the function you want to achieve.

Regards, Luis

PS - when data is sent out by UDP the IP address is 192.168.4.255 if you are working as AP only or X.Y.Z.255 if you are connected to an external network

rodion
Posts: 2
Joined: Thu Jun 18, 2020 2:04 pm

Re: IEC 61162-450 support

Post by rodion » Thu Jun 18, 2020 9:01 pm

You will find it on more or less recent ECDIS systems and VDRs (big ships essentially) to link more NMEA devices. As you know NMEA2000 was only adopted for leisure yachts. https://en.wikipedia.org/wiki/IEC_61162

The actual paper that describes the standard is paid (so stupid), but most of the info can be found on the internet. Essentially it is a multicast UDP, not broadcast or unicast and the ports are in 60000 something range

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IEC 61162-450 Light Weight Ethernet (LWE)
The LWE standard was finished in 2011 (IEC, 2011), in a sense as a result of a more than twenty year long process as discussed in the history section. It is intended for use mainly in the navigation system on the process layer, although it can also support instrument layer integration and also on ISC layer, if desired.

It uses the IEC 61162-1 sentence format (ship related NMEA 0183 sentences) with some additions from the NMEA 0183 sections related to AIS base stations. The latter components are a set of constructs to group and further characterize the sentences.

Messages consist of a number of sentences with additional data such as sentence number, grouping information, sender and receiver identities and put into an UDP datagram. The maximum size of the datagram is about 1200 bytes.

The UDP datagram is sent as a multicast to one of 16 predefined addresses. Eight of these are default addresses based on the type of sentences in the datagram. The default selection can be overridden by configuration.

Luis Sa
Site Admin
Posts: 843
Joined: Thu May 04, 2017 4:12 am

Re: IEC 61162-450 support

Post by Luis Sa » Thu Jun 18, 2020 9:33 pm

Hello,

Thank you for the information. As you should guess the response is no. The multiplexer is not capable of working in such an environment.

Regards, Luis

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