
Optical
Chopper
System
18488-D02 Rev G, September 24, 2012
Page 10
www.thorlabs.com
3.
Highlight and select Run Mode. The unit will adjust its speed and lock onto the external
reference speed within a few seconds.
4.3. Reference-Out Signal
The MC2000 supports a number of different reference out signals. For reference output selection,
highlight and select the external reference out signal from the following menu list. This list is described
in more detail in the following sections.
•
TARGET – The reference out signal synthesized internally from a unit’s crystal clock
•
ACTUAL – The reference out signal obtained from the feedback sensor reading the outer slots
on a chopper wheel
•
INNER – Reference out signal obtained from the feedback sensors reading the inner slots of a
two slotted chopper wheel. (Note: This menu item is only displayed when a two-slot blade is
selected.)
•
OUTER – Reference out signal obtained from the feedback sensor reading the outer slots of a
two slotted chopper wheel. (Note: This menu item is only displayed when a two slot blade is
selected.)
•
SUM – The reference out signal obtained from the two frequency blade 5/7 sum
•
DIFF – The reference out signal obtained from the two frequency blade 5/7 difference