'Distance to Waypoint' Difference

[janp391]

I have Raymarine ST 60 instruments and a S3G autopilot. I take the GPS information from the autopilot via NMEA out to my computer (XP SP3) and I send the steering info to the autopilot via NMEA in. So when I have a route active I can see that information in the ST 60 instruments. But if I compare the distance to next waypoint I can see a value (RNG) on the computer (OpenCPN 2.5) and a value that is app 10% higher on the ST60 instrument. Also the waypoint from openCPN will come up on the radar, also with the same error. When I arrive to the waypoint both are zero.
Is there an explanation to this? Can I correct this error?

[cagney]

Originally Posted by janp391

I have Raymarine ST 60 instruments and a S3G autopilot. I take the GPS information from the autopilot via NMEA out to my computer (XP SP3) and I send the steering info to the autopilot via NMEA in. So when I have a route active I can see that information in the ST 60 instruments. But if I compare the distance to next waypoint I can see a value (RNG) on the computer (OpenCPN 2.5) and a value that is app 10% higher on the ST60 instrument. Also the waypoint from openCPN will come up on the radar, also with the same error. When I arrive to the waypoint both are zero.
Is there an explanation to this? Can I correct this error?

Check if your ST60 is set to show statute miles (=1609m) instead of nautical miles (= 1852m).

Thomas