gasrasync.blogg.se - Humminbird nmea 2000 network backbone

#HUMMINBIRD NMEA 2000 NETWORK BACKBONE HOW TO#
#HUMMINBIRD NMEA 2000 NETWORK BACKBONE FULL#
#HUMMINBIRD NMEA 2000 NETWORK BACKBONE SOFTWARE#

But for now, NMEA 2000 is still the standard and will continue to be for a while. Newer versions of products are already starting to use Ethernet, WiFi and other methods, so perhaps we won’t be talking about this in 5 years. I think NMEA 2000’s days are numbered with the need for higher data rates and modern protocols. I’m not holding my breath though, as this battle has been ongoing since NMEA 2000 came out…. However, there has to be a middle ground where end users can see the data reasonably. Someone spitting data onto an N2K network without having it be tested and certified could be dangerous, especially if it messed with navigational data you rely on. I’m not suggesting that every random DIY’er like myself should be allowed to create and connect devices without being certified, as that could definitely be a problem. It would not only make troubleshooting easier, but it would most likely increase the amount of people and devices using NMEA 2000 networks. I think it is unfortunate that NMEA has this policy of not sharing this information.

Lots of folks have figured out the data in a PGN and helped document things that NMEA refuses to make public. In almost all cases, there will be data on an N2K network that another manufacturer’s tool won’t even understand and shows up as proprietary. This makes it very hard to troubleshoot things without paying for an interface or product that is certified and understands all of the data on the network.

#HUMMINBIRD NMEA 2000 NETWORK BACKBONE HOW TO#

For example, the NMEA publicizes which messages exist and which fields they contain, but they do not disclose how to interpret the values contained in those fields.“

#HUMMINBIRD NMEA 2000 NETWORK BACKBONE FULL#

“ NMEA divulges some information regarding the standard, it claims copyright over the standard and thus its full contents are not publicly available. The bigger challenge in troubleshooting data on the network is actually the body that governs it – NMEA. It’s not the best network in the world, and has a lot of drawbacks and issues, but it is the standard we have to deal with for now. CAN was released in 1986 with NMEA 2000 coming in the late 1990s, so it is already nearly 20 years old, and based on 30+ year old technology. NMEA 2000 networks are electrically similar to a Controller Area Network (CAN) bus network which can be found on cars and trucks.

#HUMMINBIRD NMEA 2000 NETWORK BACKBONE SOFTWARE#

Software is more complex and expensive, but can help diagnose device configuration issues. Most people should start with a hardware method to ensure the basic electrical properties of their network are sound.

Only one power injection point (unless you have a power isolator to split/isolate the power on the backbone into two halfs.There are two main ways to troubleshoot a NMEA 2000 network – hardware and software.

Max recommended number of physical nodes is 50.

The total length of all spurs in a network must not exceed 30m.

The max length of any individual spur must not exceed 6m.

Total Backbone length must not exceed 200m (32 LEN and Balanced system).

You need to assess the CAN limitations when joining two networks together:

SeaTalkng / NMEA2000 system limitations.

Depending on whether your system is Balanced or Unbalanced, depends on the maximum backbone length and maximum LEN values you can have.

You need to check you are not going to exceed the system "maximum" loadings, when joining two networks.

This example diagram shows a Total network LEN of 40, so 20 LEN is each side of the power input cable.

To assess this, you need to look at the LEN value of each connected product and try to get an even LEN value each side of the power connection. Ideally, the power injection point should be at a location where the current drawn on each side of the power connection point is equal (Balanced System).

Balanced System: The power supply into this new larger network needs to be assessed.

To check the network, when everything is powered down, measure the resistance between the Blue and White CAN wires, and check they read 60 ohms (120 ohms for each terminator +-5%).

So if you are joining two networks together, where each network has it's own two terminators, you need to remember to remove two terminators to ensure you only have a maximum of two in the system.

You must ensure that you always have a Maximum and a Minimum of TWO terminators at each end of the new network that has been created.