Knotmeter/GPS interaction w/ Wind Indicator

[Will]

I have the ST60 series wind instrument and knotmeter. It is my understanding that the knotmeter data is fed into the wind instrument to provide the "true" wind direction and speed. I plan to have a Raymarine radar/chartplotter/gps unit installed and connected to the other instruments. Since the gps gives the actual SOG, will its data (instead of the knotmeter's) be used by the wind instrument to calculate true wind direction and speed? Is there any special setup required?

 

[Bill Boudreau]

STW then SOG

The ST60 Wind instrument can calculate the True Wind information using either the Speed Through the Water (STW paddle wheel speed) or SOG (Speed Over the Ground via GPS). It takes the STW as its preference. If both are connected and the STW is reading 0 then it will not compute the True Wind information correctly. The ST60 wind does not have any function that allows you to select between SOG and STW.

 

[Steve Feinsilver]

true wind

I did not follow your response. Under what circumstances is SOG used by the wind instrument? My STG is often 0 when the impeller gets fouled, and I rely on my GPS more than my knotmeter anyway. Is there no way for the wind instrument to use the GPS info?I have GPS model 398, ST60 instruments and 7000 autohelm, all working nicely, thank you.

 

[Will]

Follow-up to Bill Boudreau

To second Steve's reply, how can one make sure the wind instrument uses the gps SOG reading? Should you disconnect the knotmeter from the seatalk bus to keep it from communicating with the wind instrument?