Horizon Fitness HTS-580 Series Operation Manual page 46

Set the instrument height/prism height before proceeding to the offset
measurement mode.
When setting the coordinate value for the occupied station, refer to Section 6.2
"Setting Coordinate Values of an Occupied Point".
Operation procedure
Press the F4( ↓ ) key from
distance
measuring mode
function on menu P2
Press F1 (OFSET) key
46
Operation
to get the
F4
F1
Display