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L011-80
Rev.
C0
2020-11-05
21. Navigate to the expected position of the target using the controls described above. For MER recording, motion artifact
will be significantly reduced by selecting a lower rate of advance.
22. Decrease the speed for fine position adjustment and advance or retract the electrode until the target is reached and
the necessary procedure performed.
23. Returning to the starting point: pressing and holding the zero button on the remote for three seconds will cause
the controller module to return the drive to its starting position at the maximum possible speed. This motion can be
interrupted by pressing the rocker switch in any direction or by changing the current speed selection using the speed
selection slider. Returning to zero can also be performed at a controlled speed by simply retracting the drive using the
rocker switch.
24. The motor unit can be removed from the drive at any point during the procedure and the operation can proceed using
the manual control and visual scale on the drive.
After completion of the procedure
25. Remove the motor unit, discard the sterile drape and return the sterilization covers to their positions on top of the drive
and on the motor unit.
26. Unplug the remote control and power cord. Store the controller unit and all its accessories in the carrying case.
Stall Detection
The torque of the stepper motor is quite high, especially when amplified by the drive screw, but the motor can be made to
stall if it encounters a physical obstruction or if the operator attempts to use the manual drive advancement knob while the
motor is operating. This is especially true at higher speeds. While this is a situation that should not occur during normal use,
a stall detection algorithm has been provided.
If a stall is detected during drive movement, the word “STALL” will appear, replacing the position number on the display, and
the drive will stop moving for approximately 5 seconds to alert the operator that a stall has occurred. Then the position will
be redisplayed and the drive will continue moving at the speed controlled by the remote. The number displayed should
be checked against the drive’s physical scale. There may be no noticeable difference due to the sensitivity of the detection
routine. A small discrepancy of less than 25 microns should not be a cause for concern.
Discrepancies of over 25 microns or frequent stall indications may require that the motor unit be removed and the manual
advancement knob be used to complete the procedure. Frequent stall indications are a sign that there may be a physical
problem with the drive resulting in excessive torque requirements, or a problem with the motor unit or controller. Contact
FHC for additional diagnostic help and to set up a repair.
