Installation manual

Simrad SP90
170
851-164510 / Rev.E
Gyro
The sonar can receive the following gyro telegrams.
• Heading, magnetic
• Heading, true
Heading, magnetic
$??HDM,x.x,M,,<cr><lf>
where (from left towards right):
Component Content
?? Tal ker
HDM identifier code for the type of system used
x.x heading in degrees magnetic
Heading, true
$??HDT,x.x,M,,<cr><lf>
where (from left towards right):
Component Content
?? Tal ker
HDT True heading
x.x heading in degrees relative to true north