Any electronic experts can help?

aluijten said:
Not completely true:

The point is that the most course computers have no ST-NG interface, only ST. Hence the connection box you referred to.
The problem with ST is that the interface speed is not very high.

For best results on the e7 multifunction with a radar overlay you need to have a "Fast Heading" signal. This is basically a message telling at least 10 times per second what the heading of the boat is.

A course computer fitted with a gyro sensor is able to deliver this. However the ST interface bus is not fast enough to cope with this (ST-NG is).
This is why a (dedicated) NMEA connection is required between the course computer and the Multifunction; to get the Fast Heading across at sufficient speed.
All other information (waypoint, XTE, etc.) can go via Seatalk.
It's only the very new course computers that support ST-NG directly, making the NMEA connection not required.

So in your case I would expect a connection from the autohelm to the e7 via the ST - STNG interface box and a NMEA connection directly from the course computer (NOT the ST6002) to the e7. The latter being one-way connection from course computer to e7.
Click to expand...

Correct me if I am wrong, but fast heading refers to the fluxgate compass data which is often sent at 10HZ.
Whereas the gyro sensor in the course computers is only for rate of turn/yaw detection and only used internally by the computer to control rate of turn and has nothing to do with fast heading...

Some forumites are overcomplicating the issue. All the OP wants is to have the E7 send AP data to the AP, and this can be done over nmea either to the ST6002 if close to the E7 or direct to the course computer which will most likely have a 0183 nmea input.

There is just no need to try to convert STNG to ST in this case.
I
 
This is quite a good site for Marine Electronics issues.
This page shows the converter.
http://www.panbo.com/archives/2010/08/raymarine_seatalk-seatalkng_converter_nice.html
Given the issues of the OP my guess would be wiring issues.
SeatalkNG is essentially NMEA2000. Devices have to be Tee'd in to it with terminators at each end of the bus.
Have a look at the diagram with the example Seatalk system with SeatalkNG multifunction display.
As these boat networks are relatively new I wonder how many installers of CAN buses have sufficient knowledge to get the systems to appear to work but are in fact incorrectly wired. Once the data flow hits a critical mass the network starts to fall over.
 
Last edited:
Talulah said:
Once the data flow hits a critical mass the network starts to fall over.
Click to expand...

Most leisure craft will never have a problem with data overflow using nmea 2000 or other proprietary flavours of it.

However this is another reason in support of sending the AP data via nmea and leaving the E7s STNG connection out of this, so its full bandwidth is intact for other high speed STNG devices eg radar or AIS.
I
 
ianj99 said:
Most leisure craft will never have a problem with data overflow using nmea 2000 or other proprietary flavours of it.

However this is another reason in support of sending the AP data via nmea and leaving the E7s STNG connection out of this, so its full bandwidth is intact for other high speed STNG devices eg radar or AIS.
I
Click to expand...

Apologies, when I talk about data overflow I don't mean too much traffic for a correctly wired network but I am refering to data conflicts where signals are clashing as devices aren't t'd in in a linear fashion. i.e. Where someone has unintentionally 't'd in to a drop cable.
Another cause of data clashes could be where the network has more than one power supply into it. (I don't know why this may cause an issue other than to say the installs say don't do it.)
i.e. Has the course computer had the SeatalkNG power switch turned on but the E7 is already powering the network.
 
Last edited:
Talulah said:
Apologies, when I talk about data overflow I don't mean too much traffic for a correctly wired network but I am refering to data conflicts where signals are clashing as devices aren't t'd in in a linear fashion. i.e. Where someone has unintentionally 't'd in to a drop cable.
Another cause of data clashes could be where the network has more than one power supply into it. (I don't know why this may cause an issue other than to say the installs say don't do it.)
i.e. Has the course computer had the SeatalkNG power switch turned on but the E7 is already powering the network.
Click to expand...

Ah, right, I see what you mean and no doubt it will be happening somewhere and the equipment will be blamed rather than the installer!
 
ianj99 said:
Correct me if I am wrong, but fast heading refers to the fluxgate compass data which is often sent at 10HZ.
Whereas the gyro sensor in the course computers is only for rate of turn/yaw detection and only used internally by the computer to control rate of turn and has nothing to do with fast heading...
Click to expand...

As requested I'll correct you.
Several Raymarine course computers will output the gyro-aided heading data at 10 Hertz via one of the NMEA outputs as an aid for the plotter to support MARPA.

As I said in a later post for the OP this is not required or expected in his configuration as his course computer supports ST-NG that has enough bandwidth to support Fast Heading, AIS and All the Nav. data.
So no NMEA required.

Cheers.
 
I assume heading data transfer is fine because the ap will work perfectly in heading hold mode?

Double power supply could be an issue

When unit was installed the 2amp fuse in the course computer blew straight away and continued to do so

Installer thought maybe the old ST50 instruments were putting too big a load on the network so reconnected their own supply to back of instruments

SUBSEQUENTLY he discovered that 2amp and 15amp fuses had been transposed in course computer as delivered from factory! Hence the 15amp circuit was running on a 2amp fuse!

However he did NOT then bither to disconnect the additional supply!

Regarding cabling and converters. My understanding was that the only function if the STNG converter was to allow pilot and e7 to access speed/wind/depth from old ST50. No converter would have been needed had we had newer instrumentsyii
A new backbone cable was ordered and used in the installation. As I said the items were specified by one of the dealers on the Raymarine stand at the LBS. he seemed to be one of the few who really understood the issue as most of the RM staff there were not really technical. Unfortunately he went busy before installation which was done by another dealer who had been staffing the stand, who comes well recommended! (which of course doesn't mean he can't make an honest mistake!)

Given what you say I reckon first step might be to disconnect the supplementary power supply to the ST50s?

Cheers
G
 
skyflyer said:
I assume heading data transfer is fine because the ap will work perfectly in heading hold mode?

Double power supply could be an issue

When unit was installed the 2amp fuse in the course computer blew straight away and continued to do so

Installer thought maybe the old ST50 instruments were putting too big a load on the network so reconnected their own supply to back of instruments

SUBSEQUENTLY he discovered that 2amp and 15amp fuses had been transposed in course computer as delivered from factory! Hence the 15amp circuit was running on a 2amp fuse!

However he did NOT then bither to disconnect the additional supply!

Regarding cabling and converters. My understanding was that the only function if the STNG converter was to allow pilot and e7 to access speed/wind/depth from old ST50. No converter would have been needed had we had newer instrumentsyii
A new backbone cable was ordered and used in the installation. As I said the items were specified by one of the dealers on the Raymarine stand at the LBS. he seemed to be one of the few who really understood the issue as most of the RM staff there were not really technical. Unfortunately he went busy before installation which was done by another dealer who had been staffing the stand, who comes well recommended! (which of course doesn't mean he can't make an honest mistake!)

Given what you say I reckon first step might be to disconnect the supplementary power supply to the ST50s?

Cheers
G
Click to expand...

Disconnect the additional supply.
Also, on the Course Computer turn off the switch that applies power to the SeatalkNG bus. It may already be off.
If this is the only supply to the CAN Bus then your ST50 instruments should now be off. If so turn this power switch back on. If not try and identify what else is providing power to the bus. Leave this switch off if St50's are still powered up.
At least now you can get down to one 12V supply. That would be the first hurdle to resolve.
Next I would check that the bus is wired linearly with terminators at each end.
(In my mind this is the most likely cause of the problem but I'm not the expert. Your installer is.)
Next, has a suppression ferrite been fitted to near where the fluxgate compass enters the back of the Course Computer?

N.B. Following a track instead of a heading is all based on cross-track error.
 
The Lazy Kipper said:
Anothing patronising "know-it-all-without-knowing-anything" response. The grumpy season is running well into spring this year :rolleyes:
Click to expand...

+1

Owning a boat isn't all about sailing it. Some of the pleasure is obtained by just being on it, and some by making things work as they should.

You could equally ask why would anyone want to sail from the UK to The Med, when you can fly there for a fraction of the cost, in a fraction of the time.

Others ask why anyone would want to upset the quiet pleasure of boating by wanting to watch TV. One of my top priorities after buying the two boats I have owned was to get a TV up and running. In The Med, I also wanted to be able to watch UK TV beamed from home to boat via mobile broadband.

Each to his own, and live and let live!
 
It would be worth checking the software versions of your E7 and converter as they have changed over the last few months:
E7 current version is 3.15
Converter current version is 1.14.

From your post #29 it seems the SPX-5's STNG could be connected to the converter and E7. If that is so, then make sure that your SPX-5's ST1 ONLY connects to your ST6002 and NOT the converter and ST50 instruments. The converter maybe connected to either the ST1 port (my first suggestion in an earlier post) OR the STNG port but not both. This is made clear in the Converter's manual p18.

The advantage of using the SPX-5's ST1 port to connect to the Converter/ST50 Instruments is that you can use the ST6002 as an instrument repeater (you did this). If you use the SPX-5's STNG port to connect the converter / E7, then the ST6002 will not repeat instrument data, and it's STBY button cannot be used to cancel depth alarms which, given my instrument / pilot head locations, I find useful.
 
malcp said:
The advantage of using the SPX-5's ST1 port to connect to the Converter/ST50 Instruments is that you can use the ST6002 as an instrument repeater (you did this). If you use the SPX-5's STNG port to connect the converter / E7, then the ST6002 will not repeat instrument data, and it's STBY button cannot be used to cancel depth alarms which, given my instrument / pilot head locations, I find useful.
Click to expand...

Not doubting your statement but that's quite a silly thing for Raymarine to do. You would expect them to make ST-NG backwards compatible without loss of functionality.

Cheers.
 
aluijten said:
Not doubting your statement but that's quite a silly thing for Raymarine to do. You would expect them to make ST-NG backwards compatible without loss of functionality.

Cheers.
Click to expand...

So the simplest solution as I've already stated is to connect the ST6002 via nmea to the E7.
It will then act as a repeater and send AP data to the SPX5.
No need for a STNG to ST convertor or to run an extra cable to the SPX5.

The ST6002/SPX5 work fine, they just need the AP data which the nmea connection can supply as well as other instrument data so the ST6002 will act as a repeater.

(this method works on my older ST4000+ where the Seatalk connection is only used to supply hdg data to my pc via a Miniplex usb multiplexer which can decode Seatalk. Everything else is done via the ST4000's nmea connection with the ST4000 also acting as a repeater for wind/depth/position etc - ie whatever is on the nmea bus from the multiplexer)

I detect some snobbery associated with these later interfaces - which 'must' be used just because they are 'newer'. Give me tried, tested & easiset to connect every time.
 
Last edited:
ianj99 said:
So the simplest solution as I've already stated is to connect the ST6002 via nmea to the E7.
It will then act as a repeater and send AP data to the SPX5.
No need for a STNG to ST convertor or to run an extra cable to the SPX5.

The ST6002/SPX5 work fine, they just need the AP data which the nmea connection can supply as well as other instrument data so the ST6002 will act as a repeater.

(this method works on my older ST4000+ where the Seatalk connection is only used to supply hdg data to my pc via a Miniplex usb multiplexer which can decode Seatalk. Everything else is done via the ST4000's nmea connection with the ST4000 also acting as a repeater for wind/depth/position etc - ie whatever is on the nmea bus from the multiplexer)

I detect some snobbery associated with these later interfaces - which 'must' be used just because they are 'newer'. Give me tried, tested & easiset to connect every time.
Click to expand...

Well it's never that simple. You have to decide what is going to be the core of the system.
Whilst the above should work it requires several components to be turned on independently.
On the other hand if you use the Course Computer as the centre of the system then everything gets powered up from that. The GPS, the Compass, the ST50 instruments and the Chart Plotter. You can now run with the Chartplotter turned off, or the ST50's turned off etc without loosing AP functionality.

Personally the ST6002 should not go direct to the E7.
For one thing you don't want to tie up that NMEA port on the E7. What happens if you now add AIS? It's going to need that NMEA port at 38400 or whatever it is.
 
Talulah said:
Well it's never that simple. You have to decide what is going to be the core of the system.
Whilst the above should work it requires several components to be turned on independently.
On the other hand if you use the Course Computer as the centre of the system then everything gets powered up from that. The GPS, the Compass, the ST50 instruments and the Chart Plotter. You can now run with the Chartplotter turned off, or the ST50's turned off etc without loosing AP functionality.

Personally the ST6002 should not go direct to the E7.
For one thing you don't want to tie up that NMEA port on the E7. What happens if you now add AIS? It's going to need that NMEA port at 38400 or whatever it is.
Click to expand...

Ordinarily I'd agree, but harking back to the OP, the simplest solution to the problem is by using nmea from the E7 to the St6002.
He can worry about your other points later.
 
aluijten said:
Not doubting your statement but that's quite a silly thing for Raymarine to do. You would expect them to make ST-NG backwards compatible without loss of functionality.

Cheers.
Click to expand...

The loss of functionality only comes about as a result of having to isolate the ST6002's ST1 connection to the SPX-5 from the rest of the system, if the SPX-5's STNG is used.


I think it would be a pity to remove the converter from the system as you'd loose Instrument Data monitoring on the E7, and would not be able to display chart vectors (Heading, COG, Wind, Tide) as overlay on the chart.

The system should work provided the connectivity is correct and the software versions up to date.

If you want to go the NMEA route then the E7 has 2 NMEA Ports.
Port 1 has an input and output with common baud rate settable to 4800, 9600, 38400
Port 2 is input only with baud rate settable to 4800, 9600, 38400 (independent from Port1)
 
You must log in or register to reply here.

Share this page

Top