ST70, STng, & N2K, an ironic tale
So I hope yesterday’s goofy contest made a point about Raymarine’s STng cabling system. I do think the design has merit, particularly for production boat building, and there’s more of interest, like heavier gauge power wires, that I’ll get into eventually. But today I’m going back to the larger point that NMEA 2000 cabling is not that big a deal. As noted earlier in these ST70/STng experiments, the data flows easier than one might think given the different connectors and network names. What really counts is that the desired data is sent and received. I learned that vividly when the first Garmins could hardly understand any N2K PGNs (messages), despite having a standard NMEA 2000 connector, and now I’ve stumbled on an ironic reminder.
Though the Raymarine ST70, which I’m falling for, can display almost all of the data being sent by the various Maretron sensors in my test network (often as a number, graph, or dial), I was surprised that it would not see some numbers theoretically sent from the Raymarine E120. I set up a go-to waypoint, expecting all the values seen above…but all (except XTE) stayed blank! Was it the E not sending or the ST70 not understanding? One way to check was trying the same drill with the Garmin 5212, now updated to firmware 3.2 which does NMEA 2000 pretty darn well. And it worked, producing those numbers above.
Better yet was observing all this using Maretron’s NK2 Analyzer (now official software, by the way). Below you can see part of the story, the glorious details of PGN 12934, Navigation Data, that’s being transmitted by the Garmin and displayed by the ST70 (full screen here). A similar screen from the E120 shows that it is not sending that particular PGN (but is sending 129283, XTE). Are you with me? Here we have three brands using NMEA 2000 together to pass data and troubleshoot a small (and easily fixed) issue that showed up within one brand. I like that! And never mind that it’s being done over a hybrid STng and DeviceNet backbone, which sure ain’t kosher but is working fine, at least in the lab environment.
Ben,
I had a ST70 installed on my sailboat a week ago and my tech connected it to my existing Maretron(Airmar) DST800 Smart NMEA2000 Speed/Temp/Depth Sensor. Unfortunately I had to tell him to take it back because the ST70 would NOT calibrate to my keel depth, speed, or temp offset settings!!!
Raymarine told him that I had to install "THEIR" older style analog Airmar Speed/Temp/Depth Sensor with an expensive junction box to convert the data to make the system work. This was crazy to me and it would have meant drilling another hole and a haulout as well as the new equipment costs.
Question for you: How can Raymarine claim NMEA2000 compatibility with the ST70 when it won't work with other standard NMEA2000 stuff? Right now, I'm really frustrated and disalusioned by this NMEA2000 stuff. Indeed, what is the benefit if it won't work with each other? My tech said that it is not a PGN issue because the data is there. It just isn't right. He also said that the Raymarine ST70 has the exact same problem with their wind stuff as well.
I liked the ST70 but, it was expensive and Raymarine tried to force me to switch over to their Seatalk NG stuff to make it work on my boat. I also had to buy adapter cables to make it work in my system. It was turning into a $2000 three inch display!!!
Also, Maretron told me to be careful because the ST70 is NOT "NMEA2000 Certified" even though the Raymarine Staff claimed it was and Raymarine lists NMEA2000 compatibility in their brochures.
What is with this crap? How can this happen? I thought that NMEA2000 was supposed to end all of this incompatibility! Instead, all of this is a show stopper for me with NMEA2000 and Raymarine products right now.
My tech actually told me to bitch about this problem on your site.
It is a coincidence that you are writing about some of the problems right now in the midst of my FIASCO with the ST70
Walt