MC2000B Optical Chopper
Chapter 5: Basic Operation
Rev A, Jul 5, 2016
Page 9
5.3. Reference-In
Signal
The MC2000B supports a number of different reference-in signals. For reference input selection, highlight and
select the reference-in signal from the following menu list.
INTERNAL – The reference-in signal synthesized internally from a unit’s crystal clock
EXTERNAL – The reference-in signal obtained from the reference input connector. (EXT Input).
INT-INNER – The reference-in signal synthesized internally from a unit’s crystal clock and referenced to
the inner slots of a 2/100-slot or 10/100-slot blade. (Note: This menu item is only displayed when these
blades are selected.)
INT-OUTER – The reference-in signal synthesized internally from a unit’s crystal clock reference to the
outer slots of a 2/100-slot or 10/100-slot blade. (Note: This menu item is only displayed when these
blades are selected.)
EXT-OUTER – The reference-in signal, obtained from the reference input connector (EXT Input),
synchronized and locked to the outer slots of a 2/100-slot or 10/100-slot blade. (Note: This menu item is
only displayed when these blades are selected.)
EXT-INNER – The reference-in signal, obtained from the reference input connector (EXT Input),
synchronized and locked to the inner slots of a 2/100-slot or 10/100-slot blade. (Note: This menu item is
only displayed when these blades are selected.)
5.4. Reference-Out
Signal
The MC2000B 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.
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 2/100-slot
or 10/100-slot blade. (Note: This menu item is only displayed when these blades are selected.)
OUTER – Reference-out signal obtained from the feedback sensor reading the outer slots of a 2/100-slot
or 10/100-slot blade. (Note: This menu item is only displayed when these blades are selected.)
SUM – The reference-out sum signal obtained from the two frequency blade (4/7, 5/7, 3/30, 8/60 and
53/60). (Note: This menu item is only displayed when these blades are selected.)
DIFF – The reference-out difference signal obtained from the two frequency blade (4/7, 5/7, 3/30, 8/60
and 53/60). (Note: This menu item is only displayed when these blades are selected.)