The procedure is based on 2 rules:
-the "home" position is defined by an encoder reading=4096 enc. units
-this "home" position must be at about 1/2 turn (
2048=1.25mm)
from the Low Limit Switch (LLS) transition. So this transition must happen
at encoder reading 2048.
-if the Low Limit Switch was also changed, then the rule is that the external fiducial must be at 230mm from the beam nominal axis when the encoder reading is 118407 ("survey" position). This rule needs the help of a survey.
The procedure is the following:
-by software (see "scanner expert task detail") or by hand (by acting on the bellow #1), set the scanner in the convenient position (LLS or survey):
-decouple the bellow #2
-connect the encoder to the control box readout
-by hand turn the encoder shaft up to have a good reading
-strongly fasten the coupler #2 Note: the encoder is absolute over 64 turns with 4096 units per turn. So, starting from 0 and turning it clockwise, one should read:
-4096 after one turn
-8192 after two turns
-...
-up to 262143 just (one puls) before 64 turns
-0 again one puls after.
-4096 after one turn ....