Log entry time 15:52:27 on June 8,2004

Entry number 124972

We tested DAQ readings of scanner positions. Rough calibration
gives change of about 90 channels per 1mm displacement of scanner.
Conclusions:
1. rprofx and rprofy variables corresponding to X and Y positions
   of scanner in right arm should be swapped.
2. Short axis potentiometer (X direction) in left arm works
   erratically, with fluctuations corresponding to +-2mm in position.    This potentiometer should be exchanged.
3. DC voltage on potentiometers should be lowered, now
   it saturates ADCs (go from ~10V to 9V ?)
4. DV voltage shows some drift, <20 channels with a period
   of about few hundred second. It should not be an issue.
5. Readings of Y position in left arm for a short time were 
   increasing with slower rate than they should. After some time
   they came back to normal rate. We should watch behavior of
   this potentiometer!
6. When left arm scanner moves in Y direction, its X readings
   flactuate. Is this coupling related to contact problems in 
   damaged X potentiometer when scanner moves?