Hologic DISCOVERY A, Technical Manual

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Discovery QDR Series Technical Manual
4-21
The program moves the TZ table to its top most position and moves the TX table
inwards until it almost touches the C-arm. It rotates the C-arm by 2 degrees to
obtain an initial estimate of the encoder calibration and then prompts:
8. The program rotates the C-arm counter clockwise (i.e., the tank assembly moves
away from the front of the machine). When the C-arm hits the AP mechanical
limit the first time, press <ESC>.Check the position value. It must be 250±5.
Adjust if necessary.
If out of range, loosen the coupling setscrew and manually rotate the encoder
until the readback is 250±5 (i.e., in the range 245-255) and then tighten the cou-
pling setscrew.
9. Before repeating the calibration procedure, rotate the C-arm back to approxi-
mately 0º by:
Typing the command:
MOVE_REL 1470<Enter>
.
10. Repeat the calibration procedure above but now, when AY hits the left mechani-
cal stop, press
<Enter>
.
Wait until the rotation completes and then repeat the calibration procedure above
but now, when the C-arm hits the AP mechanical stop,
11. Press
<Enter>
The program prompts:
and moves the C-arm back to the approximate 0
°
position. The program then
prompts:
Place a level on top of the X-ray tank assembly (not the top of the C-arm) and
use the Table IN/OUT switch on the operator panel to move the C-arm until it is
0º ±0.1º. Remove the level, wait until the rotation completes, and then repeat the
calibration procedure above but now, when the C-arm hits the AP mechanical
stop,
12. Press
<Enter>
Press <Enter> when the AR motor reaches the AP mechanical limit.
Press <ESC> to stop calibration.
Press <ESC> to stop calibration. Press <Enter> when the AR motor reaches the AP
mechanical limit.
Press <ESC> to stop calibration.
Use the Table IN / OUT switch to move the C-Arm to 0 degrees.
Press <Enter> when the C-Arm is positioned.
Press <ESC> to stop calibration.