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ETN043886-D02
K-Cube NanoTrak Auto-Alignment Controller
5.4 Settings Panel
When the 'Settings' button on the GUI panel is clicked, the 'Settings' window is displayed. This panel allows data such as scan
circle frequency and diameter, and loop gain to be entered. Note that all of these parameters have programmable equivalents
accessible through the functions on this Control (refer to the
API helpfile
for further details).
5.4.1 Tracking tab
Fig. 5.2 NanoTrak Settings panel - Tracking Tab
Circle
User Diameter
- the diameter of the scanning circle (in NanoTrak units). The circle diameter is measured on a scale such
that 10 units is the width and height of the screen. If, for example, the NanoTrak is driving a 20 micron actuator, a circle
diameter of 1 unit will result in a real diameter of 2 microns. The scanning circle diameter can have values in the range 0
to 5.0 with a value of 5.0 corresponding to one half the range of piezo motion - see Section C.1.3. for further details and
helpful hints on setting the correct circle size.
User Frequency
- the frequency of the scanning circle. The circle scanning frequency lies in the range 8.25 to 87.5Hz. The
factory default setting for the scanning frequency is 43.75Hz. This means that a stage driven by the NanoTrak makes 43.75
circular movements per second. Different frequency settings allow more than one NanoTrak to be used in the same
alignment scenario. Refer to Section 5.5.2. for more information.
Diameter Mode
- this setting allows the different modes of circle diameter adjustment to be enabled and disabled.
If '
User Adjust
' is specified, the circle diameter remains at the value set by the user, either in the User Diameter
parameter or by calling the SetCircDia method.
If '
LUT Adjust
' is specified, the circle diameter is adjusted automatically, using a table of range dependent diameter
values (set in the Diameter LUT field to the right and described below (1 diamter per range value), or by calling the
SetCircDiaLUTVal method).
Diameter LUT
- this setting enables a look up table (LUT) of circle diameter values (in NanoTrak units) to be specified as
a function of input range.
When automatic LUT diameter adjustment mode is enabled (using the Diameter Mode parameter or by calling the
SetCircDiaMode method), the system uses values in this LUT to modify circle diameter in relation to the input range
currently selected.
This LUT diameter adjustment mode allows appropriate circle diameters to be applied on an application specific basis.
Typically, the circle diameter LUT will be configured to generate a reducing circle diameter for an increasing range setting.
This fits an assumption that higher input signal readings correspond to a smaller Full Width Half Maximum (FWHM) of the
feedback signal peak being tracked, and so a smaller circle diameter is required to prevent NanoTrak instability.
Range
- the input range of the NanoTrak (1 to 13, corresponding to 5 nA to 5 mA respectively)
Diameter
- the associated circle diameter (0 to 5 NT units).
Loop Gain
- the gain setting is used to ensure that the DC level of the input (feedback loop) signal lies within the dynamic range
of the input. Increasing this value can lead to a more responsive NanoTrak behavior as the signal variation around the circular
path is enhanced. However, for a particular set up, if this value is too high, then unstable NanoTrak operation (indicated by a
fluctuating circle) can result.
Содержание NanoTrak KNA-IR
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