Mahe 36: Instruments

[vayacondios]

Yes Jef, it is still under warranty. Im waiting for them to get back to me, just thought I would ask the question. Definitely do not want to leave the helm unattended until it's fixed. There is a definite problem. I'll post after I get a solution.

[Wayward Wind]

I had the same problem which was fixed under warranty. I think the problem on WW was that the autopilot was not getting enough power under sail alone. After the techie rewired it, we have not had that problem since.
JohnC

[Cotemar]

vayacondios,

When your Autopilot takes off and deviates for no reason. Just check one thing for me. It may be a long shot. Check under your Port berth on the far left corner there is a “compass gyro”.
Is there a lot of metal items placed in that area. If so remove any large metal abjects for your next trip and see if your autopilot maintains coarse.

Again this may be a long shot, but most do not know about the interference that metal will cause in that area.

Mark

[vayacondios]

Hi Mark,
Was able to test your suggestion the last few days. I had a printer and sewing machine stored under the Port Bunk. Took them out and had one day of no deviation on the autopilot, but the second day, we had it happen once. I thought maybe it was not doing it because we had both engines going, so maybe it's a power thing but it still did it even with both engines going. It definitely has improved, but Im not sure if that's acceptable. I mean the deviation alarm is there for a reason, but what is acceptable. Would once or twice a day be acceptable? Not sure, since it's still under warranty, I would still like to get a tech to check it out, and maybe they know more.
Rozzie

[Scott730]

Rozzie
I believe it is a power issue to the drive unit, as John stated. I find any deviation unacceptable, but it will happen if the batteries are getting low and the power to the drive unit isn't enough to hold the course.

Scott

[MKB53]

I would agree that any periodic loss of direction was not acceptable.

I have had it happen in 2 situations that are understandable. 1) the wind dies /backs and there is not enough way to maintain direction. Perfectly normal. 2) I was sailing in light breezes with a strong cross current. A couple of times over several hours the alarm went. I figured that the difference between the heading and COG was confusing it.

I have never had an issue under power.

I would be interested to hear what the cause of your issues are.

The other thing that I found was that the instruments (all of them) had not been set up correctly when she was comissioned. For example the Autopilot was configured for a power boat!!

There are a number of sensitivity settings that may have some impact. I went through and set my preference for each setting and documented it in a spreadsheet. Probably need to revisit it now that I have used it in a number of different sailing conditions.

If you have not looked at the configurations I suggest that you do.

Cheers
Martin

PS: It should not cause the alarm to trigger but there are several areas up north where the charts show magnetic anomolies that could cause the course to deviate.

[Scott730]

Martin
Didn't think of the settings, mine were correct except for being in French! As you, I have never had a problem while motoring, but I did have a problem after a long sail (12 hours) in heavy wind with current (batteries were low and couldn't handle the load).

Scott

[MKB53]

Scott you have me wondering about the power situation now. I think my level was OK but it may have been quite low. I assumed that a 2kt cross current when boat speed is only 4 was enough to confuse it but ...

My thinking is:
1: If the alarm is sounding the Autopilot knows it is off track - ie: the heading info should be correct and the auto pilot smarts functioning.
2: It can't correct the heading which means either the instructions are not getting to the motor or the motor does not have enough power.

There are settings for sensitivity, maximum rudder angle, max boat speed etc which govern it's behaviour and should be checked. At low speed max rudder angle may not be enough to correct an unbalanced boat.

Cheers

[Scott730]

Martin
I have a battery monitoring system on my boat. So I can check the charge level and capacity left in the house batteries. Typically you don't want to run the house bank lower than 50% charge which is about 12.20 volts (12 volt system) with no load. My electronics and auto pilot draw a large load. So when under sail I track my battery state every hour or so and charge them as needed (I don't let the batteries go below 12.30 volt while sailing) I also watch my weather helm and reef if the helm is close to 10 degrees to the weather (major strain on the autopilot). Since doing this I have never lost autopilot under sail alone.

[Jef & Marin, Netherlands]

Hi all,
From Bangor, Northern Ireland, where we are presently waiting for the wind to drop....
Maybe the following experience is useful to you.
A few weeks ago the autopilot refused to operate in wind mode.
We had the same problem a year ago, there was no communication across the Simrad AT10 NMEA2000/NMEA0183 convertor. Meaning that a.o. the autopilot got no wind data. This small converter is located behind the fridge in our ship.
Last year the Simrad AT-10 was replaced under warranty. This solved the problem.

So somewhere just west of the Orkney islands, north of Scotland, the autopilot stopped doing wind mode again. Through many phone calls and much help from the Dutch Furuno importer Sailtron I was able to purchase 2 Simrad AT10's locally here. One as spare....
I replaced the Simrad and there is data flow again.

My guess is that the Simrad broke down due to ESD (electrostatic discharge). Or due to voltage spikes on the 12V supply.
Recently we anchored quite a lot, and the Simrad AT10 is placed less than 30 cm away from the anchor winch solenoid which will probably create huge sparks.
I have seen no anti-ESD measures on the 12V power supply (on the NMEA2000 side).
I have therefore put in anti-spike measures myself. These are:
- The AT-10 is powered on the NMEA2000 side (nmea2000 is 4 wires: 2 signal, ground and +12V). I put a 7.5 ohm resistor and a coil in the 12V power supply, and then put an electrolytic capacitor of 220 uF and a ceramic capacitor of 10 nF to ground. You lose around 0.5 Volts due to the resistor.
- I put a ferrite ring over the NMEA0183 wire, looping it through 4 times.

This circuit will strongly reduce spikes, but I don't know whether it is good enough, only time will tell. I have no memory oscilloscope with me on board, just a soldering iron and multimeter.
I could not find an electronics shop here, so I got an old PC power supply from a computer shop for free and used the components.

Maybe by now the Simrad AT-10 is not used anymore by Fountaine Pajot since the new version of the autopilot does NMEA2000, and an NMEA2000/0183 convertor is not needed anymore.

According to Murphy my Simrad AT-10 will not break down anymore, either because my measures work, or because I have a spare. Something else will break down.

By the way, a few days ago we went through the 10,000 nm mark.

Happy sailing,
Jef

[lstyles]

I cant seem to find a wiring diagram for the boat, even in French. Does one exist or has anyone made one? French is ok.
thanks
Lori

[Jef & Marin, Netherlands]

Lori,
There is none around as far as I know. Maybe PGuillemin, the US importer, who follows this thread, could ask for one to be published? It would be a great help.
Maybe FP will be reluctant to publish since:
- Electrics is designed and built-in by a subcontractor company called Pochon
- The circuit diagram is probably evolving during production, so it will not be identical for all Mahe's.

On the CD rom there is information about the power distribution. This is alternators, battery, power switches. But this stops at the fuse boxes. There is also the information on the fuse boxes.
Luckily there is a very good cable labelling. And most wires for factory options are already there.
I am presently connecting a salt-water pump. This is already pre-wired including the fuse in the starboard fusebox and wires to connect to a switch on the instrument panel. And even the hose to the sink from close to the starboard salt water inlet for the heads.

I have once published scans of the Furuno electronics diagrams, which I got from Pochon. Includes the autopilot.
This is post #33 on http://www.cruisersforum.com/forums/...s-38768-3.html
Also see Mark post #12 on http://www.cruisersforum.com/forums/...nts-38768.html

[lstyles]

Thanks Jef for the reply. I have seen those other excellent posts you reference and actually printed them out. You guys are full of information. I don't think I ever got a CD with my boat so I don't even have the battery, etc information. Maybe I should have posted to the instruments section as my real question is related to the furuno system. I am trying to figure out how to hook up my computer or ipad to the system. I saw Martin's post (#28) which intrigued me as he said that there was already wiring there to make the connection thru a multiplexer. I saw the furuno processor (in port engine area) as a way to get all the NMEA data to the multiplexer in one cable since it is receiving all the NMEA data from all sources. The multiplexer I am interested in is the iAIS (multiplexer and AIS in one and wireless for ipad). It only has one NMEA input so I figured if I could get the furuno processor to send its info to the iAIS then that would work and I wouldn't be limited to just one source of data going into the iAIS (hope that's clear). Anyway, I started looking at all the components and figured some things out but not all. First, I don't have that little thingy that lets nmea 0183 and 2000 talk. I looked in all four places that Mark said it must be in and it isn't there (port engine near processsor), behind fridge next to furuno processor there, behind helm station and behind nav station). My furuno box behind the fridge looks very different than Mark's and I was thinking that maybe they incorporated the nmea converter thing in the processor. Also one area of the processor board on the behind the fridge processor has a part labelled NMEA GPS. It has a yellow and green "input" wires. These wires join with a brown and white (and shield) coming from another part labelled "NMEA" and are labelled "out". These wires go all together in a large grey cable which I would think would go to TB7 (as it contains all those color wires) and it is supposed to be where the Instruments attach (NMEA in/out). I think I heard you mention that later versions of the autopilot didn't need the converter so maybe I have one of those. Also in fridge processor area is a grey cable with "181G MNEA" written on it and containing a brown, white and shield. It isn't attached to anything and this same wire comes out behind Nav station and again isn't attached to anything. I am not sure what it is doing there but it would be nice to use to hook up the NMEA if possible.
Looking at the main processor (port engine) I am thinking that the other way to get the NMEA data to the multiplexer is to use the TB6 spot as it is labelled "NMEA out". I guess that means I wouldnt be able to tell the autopilot what to do from my computer but I really don't think I need that capability. I guess I could also use the RS-232 port but would rather stay away from serial connections unless it would be better in long run. iAIS has a RS-232 port as well. I below posted a photo of my furuno box behind the fridge.
What do you think and let me thank you in advance for taking the time to read this and think about it. I am not very knowledgeable about NMEA so I appreciate all the help. I am sure there are others out there just like me.
Lori

[Jef & Marin, Netherlands]

Wow Lori, this is going to be even longer than you post... I'll do my best, but would not know how to keep it short AND clear. I did not know anything about NMEA when we bought our boat; a little more know but by far too little.

I'll first start to clarify a little.

First about the controller behind your fridge.
As far as I know this is the solutions for the earlier Mahe's, when Simrad's AT10 did not exist yet. It has a Furuno controller behind the fridge. I do not know it's functions except for that it must have an NMEA2000 <-> NMEA 0183 translator. Let's call this "Instruments Mark I". Year 2006/2007

In later models this expensive Furuno module was replaced by the cheap and simple Simrad AT10. Let's call this "Instruments Mark II", which I have, and Cotemar. This Simrad AT10 is the thing you could not find, of course, you having Mark I instruments. Year 2008/2009.

At this moment there is an NMEA2000 version of the autopilot. Now that this is the case, the whole Furuno equipment MAY have switched to NMEA2000, removing the need for the Simrad AT10.
This is my speculation; it has to be confirmed by somebody having a 2010 or 2011 Mahe. Let's call this "Instruments Mark III".
In this case it might be difficult to connect NMEA0183 stuff like AIS or older plotters; or there might be a provision on the new autopilot, like a configurable in/output.
Anyhow, newer AIS equipment, like the one I just bought, also has USB, avoiding this problem.

I would like to help you, but I do not know the Furuno controller of the Mark I's. You have to help yourself, but maybe my input is useful by translating it to your situation. Maybe make a diagram, and write on all wires which NMEA data is going which way. And study the autopilot manual, your can do a lot of configurations of input and output data. Also on Internet you can find a lot of information from people who have reverse-engineered the NMEA data (you have to pay a lot of money to get NMEA specifications).

First let me explain my set-up, see attached diagram. This is the standard diagram from Pochon for the Mark II's, published earlier, with my additions.
There is a 3-position switch. This gives the autopilot 3 options as input:

MIDDLE POSITION is the factory set-up. The autopilot uses the data from the Furuno GP32; including waypoint data. This is now a back-up solution for cases where both my plotter AND PC break down. Uses lowest power, useful for ocean crossings.

LOWER POSITION is what I used in 2008 and 2009. This is based on a Garmin 276C 4-inch plotter with in-built GPS. Power consumption is quite low, maybe 200 mA or so. It works very well. The moment I change a waypoint, the autopilot gives 5 beeps and the ship changes course. Nice in heavy rain. This now is also a backup solution; the plotter goes into the oven in case of lightning from thunderstorms, together with a hand VHF.

UPPER POSITION is new in 2010. It uses an ASUS UL50A series laptop as plotter with plotter software and maps. This laptop uses 0.9A at 12V despite it's big screen. This is reached by using a low-voltage SU7300 processor and LED backlight.
It also used a Miniplex Lite multiplexer. 4 inputs, a.o. for AIS. Simple, no programming required.
I used 2 inputs of the multiplexer, see the diagram:
- One input for position from the Furuno GP32 GPS
- One input for data coming from NMEA2000, like depth and STW and wind data. This was connected to the AT10's output on the NMEA0183 side, using the spare wire.
To my regret I was not able to get the waypoint data from the laptop to the autopilot. I succeeded only into getting XTE out of the multiplexer. This is probably due to the plotter software version number which had bugs. I need to upgrade this plotter software. As a consequence, if I wanted the autopilot to steer to a waypoint, I used the Garmin 276C to generate the waypoint, switch in lower position, and navigated on the laptop for having an overview on the big screen.
The 3-position switch and the multiplexer are in the instrument panel. The AIS will also go there.

OK, now about your plan to use the autopilot as multiplexer. I have also considered this, but I have not done so for the following reasons:
- This would require a wire from the AP to the instrument panel, which is not yet there. In my solution the spare wire that you describe could be used...
- More important: I worried about the system becoming confused internally. As an example: position and waypoint data would go from the Furuno GP32 to the autopilot, would be multiplexed there internally with the NMEA2000 data. The waypoint and position data would then go to the multiplexer. But at the same time your PC plotter software would OUTPUT the same data to the multiplexer. This would also go to the autopilot, if you want the autopilot to be able to head for the waypoint position on your PC screen. This is a loop.
You can think of other possible internal contradictions....
- Third, I don't have this problem since my multiplexer has sufficient inputs
- Problem with my setup is that on the PC I only get data from NMEA2000 and from the GPS, and NOT from the autopilot. There is some useful data that I can now not get on the PC, for instance the true wind speed and direction. These are not made available by the NMEA2000 wind instrument, but are re-calculated by the autopilot.

OK, now to my 2011 plans:
For above reasons I have decided to upgrade my Miniplex Lite to a new version of the Miniplex USB multiplexer. This is is fully SW configurable, NMEA input and output sentences can be enabled / disabled. (And even the multiplexer's SW can be upgraded in case of bugs). This means that IF necessary, I can break loops like I mentioned above by disabling certain outputs.
I got the module in by mail today from this Dutch company. They waited to send it to me until now because only last week there was a new SW version in it that allows SW upgrades by downloading.

Furthermore I have purchased an AIS transponder with built-in antenna splitter. It's called EasyTRX2-is (internal splitter). It is designed and produced in Germany. Nice thing is you can set an internal collision alarm. It will give a strong beep, even when both Garmin plotter and navigation PC are switched off to reduce power consumption. This is nice for our future ocean-crossing plans. Also it saves your route, and of the other ships, on a memory card. Nice for insurance claims... If you're not dead.

And the plan is to upgrade my PC plotter software and the wiring, with the aim:
- To be able to send waypoint data to the autopilot
- To see AIS both on a separate program, and as overlay on the plotter program
- To get wind data and so on the PC
-The planfor 2012: to get radar screen and overlay on the laptop....

Are you still with me?

I have a lot of back-ups, both the Furuno GPS and the Garmin mini-plotter for the navigation PC. The Garmin can even be used in the dinghy and in cities, it runs 10 hours on internal battery. Also we have a 2nd laptop, used for browsing, emails, pictures and watching DVD's. It also has the full set of navigation SW. But will use 2-3 amps i.s.o. 0.9A.

Please note it is quite complex. There is a lot of puzzling out to do. For instance, the GP32 has a software table which informs the whole system about the compass variation for the spot where you are..... This is used to define the difference between true and magnetic heading on the autopilot.....

To all:
Any suggestions are appreciated. And please correct mistakes in this explanation.
Also, I still have not figured out how to get the image from a standard radar antenna displayed on our navigation laptop.

Lori, maybe useful is the following: You were speculating that a certain wire goes from here to there. You can check this by measuring the AC voltages when the system is operating with a digital multimeter. You are then basically measuring the quantity of signal content. Do this for all wires on both sides. If all are about equal the two ends should belong to one cable.... If in doubt, then disconnect on one side and measure again.
And if you get a multiplexer, note that only part of them have optical isolators as is demanded by NMEA0183. Having this is useful to prevent undesired effects, caused by ground loops and interferences.

Also you wrote "would rather stay away from serial connections unless it would be better in long run". Well, RS232 is serial; RS424 is serial, and is the "physical" layer used by the NMEA0183 protocol, with addition requirements for example optical isolation of inputs and 4800 baud rate. So NMEA0183 is serial as well. The 38.4 Kbaud rate from most AIS transponders is also serial; NMEA2000 is also a serial format.....

I hope this helped. Good luck,
Jef

[MKB53]

Lori

I have the same instrument configuration as you and will post the details of how mine is connected but I won't be back home till March 6 which may be too late for you.

Regards
Martin