[DG] [DG11] Can ST2000+ use external Compass?

[ELAU]

I just bought a ST2000+ Tiller Pilot and found that its internal fluxgate compass is affected by my outboard in the engine well which is already on the port side of the boat (the tiller pilot on the starboard side). The magneto in the outboard seriously affects the fluxgate compass even the outboard is not started. It seems to me that the only option is to use an external fluxgate compass.

As per the owner manual, St2000+ accepts external navigational data via NMEA and SeaTalk.

I have 3 queries:

1) For external NMEA data, the manual states that ST2000+ accepts NMEA data in Track mode and WindTrim Mode and the recognized NMEA sentences listed in manual do not include heading related data (e.g. HDG, HDT, etc). Can ST2000+ recognize and use NMEA heading data (instead of its internal fluxgate) if I connect an external compass which provides such heading data in NMEA format? If yes, what NMEA heading related sentences would it accept?

2) In a post from this forum
http://forum.raymarine.com/showthread.ph...1&pid=7192
it says that:

“… one would not expect that a ST60 Compass w/flugate compass would be interfaced to the same SeaTalk bus that included a Raymarine autopilot. The ST1000 is exclusively designed to use heading data which is derived from the fluxgate compass which has been interfaced to it….”

In short, this post says that ST1000+ Tiller Pilot (which has the same owner manual and similar design as ST2000+) can only use the internal fluxgate compass.

However, in page 54 of the ST2000+ owner manual, it says that:

“Note: For installations where an ST50 or ST30 Steering Compass instrument is connected to the SeaTalk bus, and the Steering Compass has a fluxgate transducer connected, it is only necessary to carry out the auto deviation correction on the Steering Compass Instrument.”

This paragraph in the owner manual implies that a ST2000+ Tiller Pilot can connect to a ST30/50 Compass and the Tiller Pilot would use the heading information fed from the Steering Compass Instrument via SeaTalk (so there is no need to carry out the deviation correction in the Tiller Pilot).

Would ST2000+ use external heading data via SeaTalk when an external source (e.g. ST30/45/50/60) of heading data is provided?

3) If I need to use external compass for my ST2000+, what is the most economical or cheapest means to achieve this?

Thank you very much in advance for viewing and answering my queries.

[Derek - Raymarine - Moderator]

Hi Elau,

Thankyou for your enquiry.

The ST2000+ cannot use NMEA heading to overcome the effects of the local magnetic deviation, however, it can use Heading information on SeaTalk to compensate for this effect. the best route is to use a SeaTalk heading input from soemthing like an ST40 or ST50 or ST60+ compass instrument connected direct to its own fluxgate compass.

What happens is that the SeaTalk heading input provides the long term satble heading and compensates for the massive local deviation caused by the outboard motor, the internal fluxgate in the ST2000+ is still used by the autopilot for the very rapid short term control of the system.

I hope this helps?
Regards
dERKE

[ELAU]

Hi Derek,

Thanks a lot for the reply and your confirmation that ST2000+ can accept and use external heading data via SeaTalk.

You mentioned as examples that the SeaTalk heading output from ST40/50/60+ can be used by ST2000+. Can you please confirm whether the SeaTalk heading data from a Raymarine Smart Heading System (with fluxgate Compass) be used by ST2000+? Is there a minimum SeaTalk heading data frequence required by ST2000+?

Thank you.

[Derek - Raymarine - Moderator]

Hi Elau,

Thanks for the feedback,

The smart heading sensor output could be used by connecting the Seatalk from it to the SeaTalk network the ST2000+ is connected to.

Thanks
Derek

[ELAU]

Hi Derek,

Thank you very much for your reply.

I am lucky here that one member of my sailing club is now selling his old Raymarine Smart Heading System unit together with the fluxgate compass. I have downloaded and read the owner manual of the Smart Heading System and found that the heading data output from the Smart Heading System unit via SeaTalk is 2 Hz. It seems to me that 2 times of heading data update per second is a bit slow. Is 2 Hz the maximum heading data output rate I can get via SeaTalk? If no, what Raymarine equipment is now providing the quickest heading data output rate via SeaTalk?

On the other hand, in your first reply, you mentioned that "...the internal fluxgate in the ST2000+ is still used by the autopilot for the very rapid short term control of the system." Can you give more detail of the situations in which the tiller pilot would still use the internal fluxgate even when external Seatalk heading data is available.

Thank you.

[Derek - Raymarine - Moderator]

Hi Elau,
Thnakyou for your feedback,

The point you make about update rate is not really an issue, because the tiller pilot uses the internal compass still for the short term heading information - and here we are referring to updates every few milliseconds, the 2Hz update from the external heading sensor is merely to provide continuity with a long term accurate heading which compensates for the local deviation caused by the outboard motor.

Basically the two compass sources are fused in such a way that it works!

Regards

Derek