The sensors connected to Simnet can’t be found.
Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 370 / 375
Forum Description: 370 / 375 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=4232
Printed Date: 27 March 2026 at 05:01
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: The sensors connected to Simnet can’t be found.
Posted By: Aguamenti
Subject: The sensors connected to Simnet can’t be found.
Date Posted: 23 July 2010 at 09:51
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When I started the simnet system after the winter this year I cold not get any data from my wind and depth/speed sensors. I have a system that should contain the base solution of instruments as described below according to my Hanse dealer. The IS20 graphical display indicates that Address claim is toggling between OK and fail constantly and Tx and Rx errors are counted up and reset to zero constantly.
 My first thought was that one of the connectors was not plugged in correctly. I have tried out some basic stuff here and cheeked that the plugs are correctly plugged in except for the T-joiner that should be at the mast base witch I can’t find as described in the picture below from Simrad. The cable from the wind sensor goes directly into a cable stocking and at the chart table I have a 3 port T-joiner so there must be a T-joiner some where to connect the wind and Depth/Speed sensors because the sensor data is connected only by one cable forward in the boat. When trying to find out what the fault is I have disconnecting the sensor data cable at the chart table and then the IS20 graphical display does not indicate any errors in the service page.
 I will today try to find the mysterious missing T-joiner at the mast base.
Does any one have any idea on hove to continue the investigation or have had similar problems? ------------- Lars 370#469 |
Replies:
Posted By: Rubato
Date Posted: 23 July 2010 at 16:12
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Lars,
I've only read this quickly so apologies if my suggestion makes no sense. I try to diagnose these problems from the chart plotter as there is more info there. You may be doing this already. First thing I try is a total system reset from the chart plotter - this resets every instrument connected to the network (some for mysterious reasons lose there way every now and again :)). Then if there is still an issue, go into the menu where it shows which instruments are connected to the network and see if the list is complete. If it is not, then you likely have a break in the cable (connector undone) somewhere. If all are there, then it's a programming issue or a problem beyond connection with the particular instrument you're having problems with.
Steve
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Posted By: Aguamenti
Date Posted: 26 July 2010 at 11:13
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Thanks for the tip Rubato. I don’t have a Simrad chart plotter so I have to do it from the IS20 graphical. I found the T-joiner at the mast base behind a hatch in the wardrobe. I tried to find out if one of the sensor or connections to it was the problem by unplugging one at a time and then doing a global reset on the Simnet system and an auto select on the sources from the IS20 graphical display. The result was that with only the wind sensor I get no sources except from the IS20 graphical display. With only the depth/speeed sensor I get same problem as before the CAN bus is toggling between OK and fail constantly and Tx and Rx errors are counted up and reset to zero constantly and no sources cant even be updated in the sorces menue in the IS20 graphical display. I have understood now that this can be because the system is not correctly terminated without the wind instrument that has the termination built in. After talking to the Simrad agent in http://www.myhanse.com/forum_posts.asp?TID=3905&KW=filter&PID=30883#30883 The agent will send me a filter and I can try it again. The filter also acts as a terminator of the Simnet and you must have 2 or more terminators in one system. With the filter I can also disconnect the wind instrument and still have a correctly terminated system. This means that I can try the Deepth/Speed whit the wind instrument unplugged and still have correctly terminated system. I hope the filter solves the problem if not I have better opportunities to find the fault. ------------- Lars 370#469 |
Posted By: LATTE
Date Posted: 18 August 2010 at 21:08
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Could not log in as Aguamenti so now I am LATTE. The SimNet Noise filter was not the problem even if it solves some other problem see post (http://www.myhanse.com/forum_posts.asp?TID=2832&KW=noise&PN=2). Since all instruments are connected to one bus there can be one instrument that makes the SimNet bus go down ore a cable that is faulty and does the same thing.
So I dismounted the IS20 graphical and made a minimal installation according to the manual. See below. After making a global reset on the system I cold still not get any sensor in my IS20 Grapic and there were fault indicated in the Service>Simnet status display. The question now was if the IS20 graphic hade broken down and thats why none of the instruments came up. I connected a Multi function display (Garmin 4208) with NMEA2K instead off the S/D/T and set it in simulation mode and all the simulated values turned up in the IS20 graphic. This concluded that the S/D/T was faulty.  I then did the same thing but changed the S/D/T to the wind instrument and this was also not working. So the fault was an unlikely thing both S/D/T and wind sensors had broken during winter. I got both parts replaced under warranty. My guess is that the instrument broke during the winter when they were stored in the boat and the temperature came down to about -15deg. The manual say that the instrument can be stored down to -30deg. The lesson I learned from this is that I will take all instrument home during the winter and store in room temperature. The second thing I learned was that the NMEA2K has an obvious back draw that one faulty instrument ore cable can make all instruments not work and to find the fault you have to do minimal test installations. |
Posted By: Johan Hackman
Date Posted: 19 August 2010 at 09:01
It is not a drawback of NMEA2000, it is SimNet that allows "daisy-chaining", i.e. connecting instruments in series. NMEA2000 does not allow this. Instead you have "drop cables" that connect the instruments to a "backbone". SimNet, however, gives you a choice. You can connect the instruments by means of drop cables and avoid the problems created by an instrument falling out. It only requires more connectors so it will be a slightly more expensive network. Johan -------------  http://www.johanhackman.se" rel="nofollow - http://www.johanhackman.se |
LATTE wrote:Posted By: LATTE
Date Posted: 19 August 2010 at 10:40
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Johan I don’t agree.
My SimNet status diplayed that the Can bus toggled from OK to Fail this means to me Can Bus errors and if the bus cant turn on no instrument will turn on. Since the instrument all talk on the same two physical lines and has to be synchronized the fault is all over the bus and every device is affected or the analyzing device is faulty. To only have drop cable devices will not solve the problem since all nodes anyway are on the same bus. I found a useful manual at http://www.odva.org/portals/0/library/Publications_Numbered/PUB00027R1_Cable_Guide_Print_Copy.pdf for the DeviceNet(NMEA2000)and in chapter 5 found a guide to analyze symptoms. Quoted from the guide --------------------- ANALYZING SYMPTOMS Use the following to analyze the most common symptoms and their likely sources. Most devices have LEDs, some have alphanumeeric or other displays. If any of these show error codes or messages, read the manufacturer’s data sheets to intrepret the codes. Bus Errors Bus Errors SYMPTOMS: 1. Nodes intermittant-they drop off suddenly and unexpectantly 2. LEDs or other displays indicate “buss off” errors. CHECKS: – Use protocol-aware tool to measure bus error rate. SUGGESTED ACTIONS: – Node baud rate set incorrectly affects other nodes when it attempts to go online – Replace suspected faulty device and re-check error rates – Intermittent cables - check by shaking/bending/twisting the suspected cable or connection while looking at the error rates ----------------------- /Lars |
Posted By: Nereide
Date Posted: 19 August 2010 at 10:51
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from my experience, as this has happened 3 times, and for unknown / unidentified reasons
is that i have to do system reset / reinitialization, like Rubato says.
i do have CX44, but i do it from autopilot AP26 - all simrad IS12.
each time this as done the trick.
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Posted By: Johan Hackman
Date Posted: 19 August 2010 at 11:01
I am no expert but I have to defend what I previously wrote. It might not be applicable to your problem though. If there is something wrong with the network itself, say, the backbone is not working, then of course it doesn't matter what the network architecture is. What I wrote is more of a theoretical knowledge, most of which I have picked up at this excellent site: http://www.panbo.com - www.panbo.com I am sorry that I cannot be of any help for your specific problem. Johan ------------- http://www.johanhackman.se" rel="nofollow - http://www.johanhackman.se |
Posted By: LATTE
Date Posted: 19 August 2010 at 13:52
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The panbo site is excellent I have been there a couple of times and I also could see your GMI 10 power subject is it solved now?
My problem is solved the way I explained in my pervious post by making minimal installations and in that way i could find out what parts that failed. I posted that so other people can learn from it sorry if my written words are hard to understand. I agree with you “the backbone is not working ” and from what I have read and understood is every instrument a part of the backbones physical layer and when one instrument or cable dysfunctions it can affects the backbone and all devices as in my case Can bus=Fail. /Lars |
Posted By: Johan Hackman
Date Posted: 19 August 2010 at 15:07
Lars, I understood what you wrote. Maybe I shouldn't have written "I am sorry that I cannot be of any help for your specific problem" but I was typing fast.  I was merely pointing out that you can connect instruments to SimNet in a way, consistant with NMEA2000 rules, that will allow an instrument to fail without the rest of the network breaking down. However, the simplest way to install a SimNet network is to connect the instrument in series and that's probably how it is done on most boats.When it comes to the wind sensor it has a built-in terminator so it becomes by default one of the ends of the backbone. I don't know if this means that the network is affected if the sensor breaks down. I returned the GMI10 to the shop because it was an "older" model that wouldn't take its power from the NMEA2000 bus. I later learned that the "new" version is not yet on the market so maybe I should have kept it. Instead I read the wind angles and speed from my IS20 Graphics. I put the cover on my wind instrument because I didn't even want to see it. That's how bad it worked.  I am glad that you got the faulty parts replaced and that your problem now is solved. Johan ------------- http://www.johanhackman.se" rel="nofollow - http://www.johanhackman.se |
Posted By: LATTE
Date Posted: 19 August 2010 at 16:27
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Sorry to here that GMI 10 didn’t worked as supposed seems to me that manufacturers put tings on the internet as if they existed long before thy reach the market. I have been looking at the GMI 10 for myself for a while to get a digital display that can lock analogue:) I have a Garmin MFD that works perfectly with NMEA2K.
Yes the devices can detect when they are failing and disconnect themselves but if the fault is in the devices connection to the bus within the device (physical layer) this won’t help since it is the connection part that’s failing. For instance the node baud rate set incorrectly affects other nodes when it attempts to go online or some other short circuit problem inside the devices signal wiring. All devices talk on the same two physical lines so there will be interference as if to people speak at the same time. /Lars 
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