Hologic DISCOVERY A, Technical Manual

Page: 88 / 274

Discovery QDR Series Technical Manual
3-36
5. Repeat the calibration procedure above but now, when AY hits the left mechani-
cal stop, press
<Enter>
.
The program then starts AY moving to the right and prompts:
6. When AY hits the right mechanical stop, press
<Enter>
.
The program then switches to graphics mode and draws the Encoder Vs
Distance calibration grid. It steps the AY motor to the left in one inch
increments until the motor hits the left mechanical stop, and then steps
the AY motor to the right in one inch increments until the motor hits the
right mechanical stop. The program plots the encoder data during the
scan (in raw encoder units, 0-4095).
Note: Press
<Esc>
anytime during the scan to abort the calibration procedure.
When the calibration scan completes, the program computes the linear fit for
both the positive and negative motion. The linear fit parameters are displayed at
the top left and top right of the plot in the form Y = Int Slope * X. The
two slopes (e.g., 86.6 and 86.5) should be within 0.3 of each other.
The program displays the positive and negative limits as horizontal dashed lines.
Press <Enter> when the AY motor reaches the RIGHT mechanical
limit.Press <ESC> to stop calibration.