More SimNet, plus the handy AT10
I thank Dan for yesterday’s NMEA 2000 homily (more guest blog entries welcome!), but I do want to play devil’s advocate. I’ve had my head in the Simrad Yachting 2008 catalog today (unfortunately not online yet), and I’m ever more impressed with how thoroughly the company has adopted its SimNet version of N2K. All those yellow lines in the diagram above, bigger here, represent SimNet data bearing cables (power too in many cases). I hadn’t fully realized that Simrad has N2K GPS, depth, and wind sensors as well as the rudder angle and compass that were mentioned with the new autopilots. Of course the AI50 Class B AIS would also plug and play nicely with this typical sail system, and give it a backup GPS, as long as it was powered up. And the SimNet cabling has a lot going for it, like a tiny plug that’s the same on both ends, and the ability to daisy chain, even the backbone in some cases like that RS86 VHF.
Now SimNet does not have the field attachable connectors, and many other doodads available with standard NMEA cabling, but you could make standard cabling work in this system…with a lot of patch cables. Heck, Furuno is even daisy chaining DeviceNet cables, though I don’t think that’s NMEA approved. And Simrad clearly states in its catalog that male and female adapter cables are available to “easily connect” their N2K gear to a standard backbone. You can find more info in their SimNet manuals, which include details on a little known but very handy NMEA 0183/2000 AT10 translator. This device, shown below, costs about $100 (from Maretron and elsewhere) and automatically converts quite a few common data sentences both ways. It could be darn useful in some installs. By the way, if Ethernet would be so much better than N2K—see yesterday’s comments—why the heck isn’t Simrad, or Furuno, or Garmin, or Raymarine, or anyone making Ethernet compasses, GPSs, depth sensors, etc.? It seems obvious that they aren’t particularly concerned about working with each other’s gear But I think the momentum of NMEA 2000, with some push by some properly pesky customers (like Dan and Russ), is going to let us do that anyway.
After some research I found that the least expensive way to go from Simrad to standard N2K was to take a Simnet cable and cut one end off and install a Maretron field attachable connector. This works perfectly with my Maretron backbone and my Simrad AP-16 autopilot.
Looking at the cables now wonder if the shield is connected to ground in Bob’s replacement of Simrad connector with Maretron field attachable connector. BUT found out on Simrad Autopilot Computer(AC12/42) they don’t connect the shield!! and maybe ont their simnet rudder feedback unit as well (rf25).
How much shield is connected in a system anyway?
And jumping ahead on Actisense box – connect shield to system or connect drain wire (much easier)?
I’m trying to connect a Maretron WSO100 to a Transas navigation system, via a PC comm port. I have the AT-10 2000-0183 Adapter. What baud rate is the output of the converter?
So far, I’m unable to get any signal.
Any troubleshooting hints?
Bud, The AT10 NMEA 0183 output is the standard 4800 baud. I tested one since I wrote this entry, so you’ll find more in the update:
It’s been a long time since I fooled with any Transas programs, but I’d guess you may have limited success with the AT10. A Maretron USB converter will probably get more data to Transas from the WSO, faster too, but I’m not positive. Please tell us how it goes.