Some help connecting up simrad gear

[natew]

So, I bought basically one of everything that simrad makes and now i'm trying to get it all connected together. I've run into a couple of stumbing blocks that I can't figure out.

I am trying to tie in my wind instruments and depth (IS20 Combi package), etc. to both the provided displays and my Chartplotter (NSS 9 Evo2). The chart plotter is connected to the Autopilot and everything else via NMEA 2000 the instrument package and displays I have have all these simnet connectors and joiners. Currently I have the wind, depth, speed sensors connected into the simnet 3 port joiner (yellow colored ports), on cable is then connected into the IS20 Combi display, another cable then connects from the IS20 Combi into the IS20 wind instrument display, I then have a Simnet to NMEA 2000 cable which oddly connects into the port labeled "OUT" on the NMEA 2000 network in place of a terminator.

Does that sound correct? I cannot confirm this via the manuals or any documentation anywhere, all I see is that with NMEA 2000 you are supposed to connect each device directly into the NMEA 2000 network of course I don't have all the cables to do that.


Second question I have is with the Radar and the GoFree wifi both use the "Ethernet" port on the back of the NSS9 display. Since the GoFree has two Network/Ethernet ports do I connect the go free into the chart polotter and then the radar module into the second port on the gofree or do I need something else?


Thanks!

[Suijin]

With NMEA 2000 you basically connect all of the devices to the backbone with the "T" fittings and then terminate the end plug. Power in one end, then daisy chain the devices in with the "T" connectors, and then terminate the other end. You can bring power in through one of the "T" connectors (see below) but you will need to terminate both ends of the backbone.



Failure to terminate properly will lead to failed communication between the devices.

As far as the network goes, the question is whether the radar is using the ethernet protocol to talk to the NSS9. It may simply use CAT 5/6 cable, I'm not familiar with that unit. Hopefully someone else here will know. There are two ports on the GoFree in case you want to connect it to another network device. If possible I suggest you "dry fit" your components in advance of installation and work out the connection issues and get a fully functioning network/system before you run cable and install devices.

[natew]

Thanks Suijin!

That's what I was afraid of when I started connecting all of this.

As for the simrad networking, that's why I quoted the ethernet part of that sentence because it looks to be proprietary connectors as they are all round type multi-pin connectors similar to NMEA but a bit larger.

Oh and it wouldn't be nearly as much fun if I had not run all the cables first.

[MarkSF]

Simnet is NMEA2000, just with a greatly improved connector system. I really like the Simnet system for two reasons :

1) The cable connectors are much smaller and easier to thread through small gaps

2) Much greater flexibility of connection

I have a Simnet network connected to an NMEA 2000 one. I connected the Simnet to one of the NMEA 2000 drops (to a T). This way the NMEA 2000 is still properly terminated at the ends. On the other end of the drop is a Simnet 3-way connector, with my Simnet devices plugged into it.

Now I know this is a bit naughty according to NMEA2000 rules, but it works.

In other words, in the diagram in the previous post, the Simnet replaces one of the drop cables, NOT a terminator.

[colemj]

Originally Posted by MarkSF

I connected the Simnet to one of the NMEA 2000 drops (to a T). This way the NMEA 2000 is still properly terminated at the ends. On the other end of the drop is a Simnet 3-way connector, with my Simnet devices plugged into it.

Now I know this is a bit naughty according to NMEA2000 rules, but it works.

If I am understanding your description correctly, this is perfectly fine and acceptable by NMEA2000 standards. You have simply used the Simnet connector as a multiport box on a drop. As long as the total drop length (Simnet cable to backbone + instrument cable to Simnet box) is not out of spec, everything is OK. We do the exact same in our system.

Mark

[paulnorkett]

I have recently fitted a simrad system in my old Nauticat comprising NSE12, AP24/AC42/RC42/RF300 with a universal linear drive for the autopilot. Had a few problems getting it all to work but most of these were because of me not interpreting the instructions properly. What got me through the installation was a first class supplier with excellent technical backup (The Service Centre, Wareham, Dorset). It is all working OK now and have just fitted an Airmar transducer and the simrad BSM 1.I just hope it will be reliable. My advice to anyone DIY fitting a simrad system is buy it from a supplier who provides technical back up and not from a discount box seller who will just say return it if anything does not work.