[DG] [DG11] ST50 anemometer in SeatalkNG network?

[capglider]

Hi, My Dehler 34 sailing yacht is equipped with the following instruments:
- RM log & depth ST60+
- RM autopilot ST6000
- RM anemometer & instrument ST50
- RM Axiom 7 MF
- B&G V50 VHF

I very recently completed all of this with the Seatalk to SeatalkNG convertor and the SeatalkNG convertor kit.

All communications work fine except for the ST50 anemometer (I have not yet tested the autopilot, but do not expect any problems).
I am pretty sure that all cabling is done properly.I double checked if the ST50 is linked to the ST60 instrumentsand that is indeed the case.

However: none of the ST50 data seems to be available in the network:
- the Axiom does not find any windspeed data sources
- the ST50 can not display true windspeed (instead error message "--" is shown)

My questions:
1) is it possible to include the ST50 in this network
2) If yes, which additional products are required and what kind of steps do I need to perform to solve this issue ?

[Derek - Raymarine - Moderator]

Hi capglider

Thank you for your enquiry,

The ST50 instruments use very early SeaTalk data sentences and so are not directly compatible with the converter and STng, we recommend replacing the ST50 wind display with an i60 wind display, this will connect to the ST50 masthead Transducer.

It is also important to make sure the SeaTalk to Stng converter is connected correctly, it must only have one power supply and this should be from the STng backbone, ensure that there is no power from SeaTalk reaching the converter.

Note that the ST50 display will not indicate True wind speed unless it is receiving boat speed through the water, this would also suggest that the ST50 Wind display is of an early type as it should be receiving Boat speed through the water data from the ST60+ Speed display.

Please upgrade the ST50 wind to either an ST60Wind or an i60 wind display.

Regards

Derek

[capglider]

Thanks for your reply. Good to hear that I will be able to keep the masthead transducer!

Having checked the backside of the i60 display online, I wonder how to connect the existing cables of the ST50 to this unit? Te cables now go directly into the back of the ST50 display, without any Seatalk connectors. Do i open up the cable from the transducer andsimply connect the individual wires to the connectors 3 through 7 asshown in par. 4.5 of the i60 manual ?

[Derek - Raymarine - Moderator]

Hi capglider,

St50 used moulded on plugs to connect the transducer and the SeaTalk, i60 uses spade connectors for the transducer and a moulded plug for the SeaTalk.

The cable from the transducer which has a plug moulded on to the end of it, can be cut, the cable sheathing peeled back and the transducer cores connected colour for colour to the spade connections on the back of the i60.

Please see this link here for furthe rinformation.

Regards

Derek

[capglider]

Great, thanks !

[Derek - Raymarine - Moderator]

Hi capglider,

You're welcome

Thanks
Derek

[capglider]

Yesterday I replaced the ST50 windmeter by a ST60Wind found on ebay earlier. Mast unit and cable where reused.

All seems to be working fine technically, so that's great.

However, I have the impression that the wind speed as indicated was incorrect. Forecast was 30knts, with 40 knts gusts, and it was pretty heavy. The wind meter never indicated more then 22knts. I have not been abel to verify with neighbouring boots,but is there any known information about misreadings when combining ST60Wind meter with ST50 mast unit?

[Derek - Raymarine - Moderator]

HI Capglider

The hemisperical gups on the later anemometers are more efficient than the older squarish style cups and so the new cups will spin faster and your wind speed indicated will overread. To accommodate this change, all wind instruments manufactured after ST60 - which was when the new cup design was launched, have a speed calibration to adjust the wind speed - you should find a calibration factor of 0.7 will provide a more accurate wind speed
Regards

Derek

[capglider]

Hi Derek, thanks for your fast reply.
You probablymean the other way around? I have kept the old mast unit (with squarish cups), and replaced the ST50 instrument with an ST60+ Wind instrument. I have the feeling the instrument "underreads". Will setting the calibration to 0.7 not make things worse rather than better? If so, can I also calibrate with a factor of 1.3 in stead?

[Derek - Raymarine - Moderator]

Hi Capglider,
Thankyou for the feedback,

Apologies, yes, the older Squarer cups will rotate slower and so increase the cal factor to 1.3 to increase the wind speed on the display.
Regards

Derek