[CA] [CA11] ST60+ Displaying HDG in Magnetic but COG in True

[kevin.coffey]

My system consists of a C90W MFD, SPX-10 course computer, RayStar 130 GPS Receiver, ST6002 SmartPilot Controller, ST60 speed-depth-wind instruments, and a couple of ST60+ Graphic Displays.

The annoyance is that the ST60+ in the cockpit, most often set to show both heading and COG, displays heading in magnetic (preferred) and COG in true (unwanted) when the MFD is off (most of the time). The ST60+ displays both heading and COG in magnetic (good) when the MFD is on. Is this because the 130 can only give COG in true and the only source of variation information is in the MFD?

Is there any way that the ST6002 or SPX-10 can "translate" COG in true to COG in magnetic for display on the ST60+? Any other way to see both heading and COG in magnetic with the MFD off, which minimizes power draw while helpfully making obvious the difference between heading and COG?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Kevin,

If an external magnetic variation value is available from SeaTalk or NMEA, this will be used by the ST60+ Graphic Display. While the MFD is capable of supplying the system with magnetic variation, the GPS sensor is not. If an external variation input is not available, use the button to set VARIATION ON (See the Variation subsection of the User Calibration chapter of the ST60+ Graphic Installation and Operation Guide, then use the track and reset buttons to set the correct magnetic variation value. If you do not want to display the variation value, use the button to set VARIATION OFF.

[kevin.coffey]

Thanks, Chuck. Long time since you originally replied, but now I have a related question. If putting variation in the ST60+ so that magnetic course can be displayed even with the MFD turned off, is it possible, other than manually turning variation in the ST60+ off, to have the ST60+ "prefer" and use the variation from the MFD when and if the MFD is turned on and transmitting on the bus?

[Chuck - Raymarine - Moderator]

Kevin,

Typically, variation should only be entered via one device within the system and that device will be operated whenever the system is used. I believe that the system may function in a manner such that the last device capable of configuring variation and which in turn has configured variation will cause that value to be used by all devices within the system until such time that variation is configured by another product. Were this to be so and should there be times when the MFD will not be operated, but the instruments will be operated, then it would be my recommendation that variation be configured from the instrument rather than from the MFD (assuming that the instruments will also be operated whenever the MFD is operated). Unfortunately, the ST60+ instruments are no longer within our equipment suites and our repair centers can no longer service them. As such, I would be unable to verify what has been specified within this response. I can only advise that you verify within your own system that when variation has been configured within the ST60+ instrument that that COG and Heading values reported within all devices within the system match.