The plusminus command is used to specify the direction of scattering
for the monochromator, sample, and analyzer.
The syntax for the plusminus command is:
plusminus
+/-1 +/-1 +/-1
OR
plusminus +/- +/- +/-
The monochromator scattering direction is fixed for a given instrument
and cannot be changed using this command.
NOTE: All angles are positive in the trigonometric (i.e.
counterclockwise) sense. The standard W configuration is either plusminus
+ - + OR plusminus - + - depending on
the sign of the monochromator scattering direction.
The plusminus command can also be accessed
from the GUI by selecting the Experiment
tab from the Setup
top-level tab. To change the scattering directions for the
instrument, the green button at the bottom of the tab must be changed
from "Monitoring
... Click to allow changes" to "Changing ... click
to monitor". Select
either Plus
or Minus
from the blue pull-down menus and commit the changes by clicking on the
blue "Update
Parameters" button. NOTE that the MONOCHROMATOR
pull-down menu will not allow you to change the initial scattering
direction as this is fixed by physical constraints on the instrument.
