Navitar Motorized Zoom Systems Instruction Manual for Windows
Revision B
Page 14 of 23
2/17/2004
In the following procedures, “near” is the bottom of travel and “far” is the upper
end. “Forward” motion is from “near to far” (bottom to top) and reverse is the
opposite.
Environmental conditions (temperature) will have a small impact on position
sensitivity, therefore the systems should be stabilized and in a controlled
environment for absolute repeatability.
After a “count to position” is established, the motor Accel and velocity settings
should stay constant, as they determine mechanical position performance.
8.6.1.5 Customer Setup - Reverse Backlash
This value specifies the number of steps the motor will overshoot the destination
count before turning around and returning to the final value, in the reverse
direction. This feature is designed to remove any mechanism backlash when
motors are switching from reverse to forward direction. If the user is not
concerned about backlash removal in the reverse direction, set the value to zero.
If the mechanism has large mechanical tolerances, increase the backlash value.
A larger value will result in slower operation because the motor has to overshoot
the destination by the specified number of steps and then return back to the final
target value. (Note: Assuming “0” has been set to “near”, this method is an
improvement, but not as accurate as returning to home).
8.6.1.6 Customer Setup - Forward Backlash
This value specifies the number of steps the motor will overshoot the destination
count before turning around and returning to the final value, in the forward
direction. This feature is designed to remove any mechanism backlash when
motors are switching from forward to reverse direction. If the user is not
concerned about backlash removal in the forward direction, set the value to zero.
If the mechanism has large mechanical tolerances, increase the backlash value.
A larger value will result in slower operation because the motor has to overshoot
the destination by the specified number of steps and then return back to the final
target value. (Note: Assuming “0” has been set to “near”, this is the least
accurate of all, and should not be used in any kind of a Metrology Application).
8.6.1.7 Customer Setup - Zero
The mechanism has two sensors ‘Home’ and ‘Limit’. The zero-configuration
specifies which end of the travel is to be considered the ‘Home’ position, near or
far. The selection is made by operation of two radio buttons. If the ‘Near’ setting
is selected, the mechanism will move to the near end of the travel and consider
this the ‘Home’ location and count of 0. If the ‘Far’ setting is selected, the
mechanism will move to the far end of the travel and consider this the ‘Home’
location and count of 0.