3.4 Commands
49
3.4.5 Chopper Operation Commands
Run/Stop Chopper Motor
MOTR(?) {
z
}
Set (query) the chopper motor state to {to
z
= (
OFF 0
,
ON 1
)}.
MOTR ON
is equivalent to pressing
Run /
Stop
when the motor is stopped.
MOTR OFF
is
equivalent to pressing
Run /
Stop
when the motor is running. Braking current
is applied to bring the chopper blade to a stop (i.e. power to the chopper
head is not immediately turned off).
»
MOTR ON
Example:
»
MOTR?
ON
Frequency Monitor
MFRQ?
z
Query the monitored frequency of {
z
= (
OUTER 0
,
INNER 1
,
SHAFT 2
,
SRCE 3
,
SUM 4
,
DIFF 5
,
CTRL 6
)}.
Because Sum and Difference Reference Outputs are synthesized from
the Source Clock, queries of
SUM
or
DIFF
will return the
target
synthe‑
sized frequency
(𝑛
OUTER
± 𝑛
INNER
) × 𝑓
ref
and not the instantaneous
mea‑
sured
frequency given by
(𝑛
OUTER
± 𝑛
INNER
) × 𝑓
shaft
.
Similarly, a query of the
CTRL
frequency returns the
target
value of the
control frequency
(𝑓
source
×
𝑛
𝑚
)
, and not the measured value of the se‑
lected control track.
»
MFRQ? OUTER
Example:
3500.0171
Number of Blade Slots
SLOT? [
z
]
Query the number of slots for the installed chopper blade [with
z
= (
OUTER 0
,
INNER 1
)]. If no optional parameter is specified, returns (
i
,
j
), where
i
is the number of slots detected on the inner track, and
j
is the number of
slots detected on the outer track. For single‑track blades,
i
= 0.
If
SLOT?
is queried before running the chopper motor, the returned slot
count may be inaccurate.
»
SLOT?
Example:
10, 100
»
SLOT? INNER
10
SR542 Precision Optical Chopper
