Topcon mmGPS 3D Paver, Reference Manual

Page: 127 / 288

Control Menu
P/N 7010-0781
3-57
Valve Offsets
The valve offset calibration determines the minimum electrical signal
required to begin moving the machine’s hydraulic cylinder to return
the screed to on-grade. Valve offsets simply determines the electrical
requirement, valve gain determines the speed of the cylinder.
The system requires four valve offsets, which must be individually
calibrated upon initial setup or after hydraulic maintenance. If valve
offsets are set too low, the screed will not reach on-grade. Likewise, if
the valve offsets are set too high, the screed moves too far and
overshoots on-grade.
Factory preset for valve offsets: 0
1. Raise the screed so that both sides rest a few inches above the
ground.
2. At the control box, tap
Topcon Logo Control Valve offsets
.
3. Press the
Raise left Set
button to enable the entry box and
calibrate the left valve offset value (Figure 3-56 on page 3-58).
The control box begins sending a raise signal to the left valve and
the grade indicators display the currently active offset.
NOTICE
Perform valve offset calibrations before adjusting
elevation and slope valve gains. If valve offset is
altered, valve gain adjustments need to be
performed again.
NOTICE
When using the control box on different machines,
perform valve offset calibrations and valve gain
adjustments for each machine.
DANGER
Since the screed is about to move,
automatically
,
HANDS and FEET should be clear of the screed!