Set-Up and Operational Functions
The display contrast might need to be adjusted if your viewing
angle changes. The Trumeter STN displays have a very wide
viewing angle, and don’t require frequent viewing angle adjustment.
There is a chance that the display will show rolling clear bars
through the displayed text. If this anomaly is seen, select the other
display type (A or B) which will make a subtle change in the way the
display is dealt with. There is a very good chance that the rolling
bars will not be seen with either setting.
Rotation Compensation is an option which should be used if you
are rotating your blade as well as changing grade. The rotational
knob is to be manually adjusted to the same rotation as the blade.
We recommend that you mark certain angles on the blade so
accurate grade calculation may take place.
These following items can - and probably will - operate the
hydraulic valve. Be careful with their use!
If you’re in Proportional time mode:
To ensure a consistent dead band (set below) and stability, the
minimum pulse width sent to the valve for very small tilt errors must
be set to the proper value. Various different directional valves have
vastly different minimum pulse widths necessary to actually open
them and deliver oil. This screen shows the minimum pulse width as
it is currently set. Push the “Test” button to adjust the minimum
pulse width.
If you select “Test”, the down valve is pulsed twice per second;
the initial pulse width is 10 ms. Use the up/down arrow keys to
change the pulse width until the machine just begins to move.
Remember that pulse width. Push the Chg Dir (Change Direction)
button, and repeat the exercise until the machine just starts to move.
Remember that pulse width. In either the Up PW or Down PW
screen set the lower of the two numbers you just remembered in that
window. Push “Stop” to save the number and turn the valve off.
Note that either the “Stop” button or the Power button will
turn off the valve drive in a panic situation, and return you to the
Minimum PW window. Also, the valve will shut off automatically
after 20 seconds without any buttons being pushed.
If you’re in Proportional current mode:
Some variable volume valves have a minimum drive duty cycle
(DC) below which their oil flow is zero. The LevelMaster 2C will,
when oil flow is required, provide a minimum duty cycle as set in
this mode.
If you select “Test”, the down valve is energized with a 6% duty
cycle signal. Use the Up/Down keys to adjust this duty cycle until
the machine just begins to move. Push the “Chg Dir” button to
verify your setting with the up valve energized. Push the “Stop”
button to terminate the test and store the value just selected.
Note that either the “Stop” button or the Power button will
turn off the valve drive in a panic situation, and return you to the
Minimum PW window. Also, the valve will shut off automatically
after 20 seconds without any buttons being pushed.
As a result of timing constraints in the valve driver hardware, the
duty cycle (DC) moves in increments of about 6%.
LevelMaster 2C Instructions v0.5 (Grader) (8/7/03) page 5 of 14
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