Hypertherm SensorOHC - Manual (Page 13)

Section 2: Operation 9
Section 2: Operation
Operation Modes
The two basic modes of operation are “Automatic” and “Manual”.
Note: The control unit must be calibrated prior to use. See calibration instructions in this guide.
Automatic Operation
“Automatic” mode is active whenever the “Manual” input on pin-3 of the 15 pin I/O connector is
open. During “Automatic” operation, the height of the torch is constantly maintained at the set
height. When the unit is operating, the green “In-Position” front panel light and corresponding I/O
output will indicate that the unit is maintaining the set height. At any time during “Automatic”
operation the set height can be changed and the unit will quickly respond and position to the new
desired height. The ‘Up/Down” switch can be used at any time to temporarily override automatic
operation and force the lifter to move in the desired direction. As soon as the Up/Down switch is
released, the unit will return to automatic operation. Activation of either limit switch will prohibit
further motion in that direction.
Manual Operation
“Manual” mode is activated by connecting the input on pin-3 of the 15 pin I/O connector to the
signal Ground on pin-2. In manual mode, the unit is controlled by using the Up/Down switch only.
The control will not respond to the “Set Height” and will stay fixed in the position that it was last
driven to using the Up/Down switch. The Up/Down switch has two speeds depending on how long
it is held active. During the first second, the control will move at low speed to allow the operator to
finely position the torch. The low speed can be maintained by pulsing the Up/Down switch. If the
Up/Down switch is maintained for more than one second, then the control will shift to full speed to
drive the lifter in the desired direction. Activation of either limit switch will prohibit further motion in
that direction.
Errors
During “Automatic” operation mode, if the sensor should come too close to the plate (less than
1/10 inch or 2.5 mm), the unit will automatically force a retract in an attempt to avoid a crash. This
error condition and others listed in the following figure will be indicated by a code number that
flashes on the red “Error” front panel light. Any error will also cause the “Error” output on the I/O
connector to become active until the error is corrected.