Agilent Technologies 53220A, Руководство пользователя

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53220A/53230A User’s Guide 67
53220A/53230A Measurements 3
[SENSe:]ROSCillator:SOURce:AUTO {OFF|ON}
[SENSe:]ROSCillator:SOURce:AUTO?
(query form)
-
INTernal
selects the counter’s internal 10 MHz oscillator. The signal is a
0.5 Vrms (into 50
Ω
) sine wave. The internal oscillator signal is also present on
the counter’s rear panel
Int Ref Out
connector.
-
EXTernal
selects an external reference signal applied to the rear panel
Ext Ref In
connector. The signal must be:
• 1 MHz , 5 MHz, or 10 MHz
• 100 mVrms to 2.5 Vrms
• sine wave
and the frequency must be specified by the
SENSe:ROSCillator:EXTer-
nal:FREQuency
command.
-
:AUTO ON
enables automatic selection of the reference oscillator source. If a
1, 5, or 10 MHz signal is present on the counter’s
Ext Ref In
connector, source
EXTernal
is set. If a valid signal is not present or is lost , the source automat-
ically switches to
INTernal
.
Note that specifying an oscillator source (
INTernal
or
EXTernal
) using
[
SENSe:]ROSCillator:SOURce
disables automatic selection.
-
:AUTO Off
disables automatic selection of the oscillator source. The source
is then set by the [
SENSe:]ROSCillator:SOURce
command.
The reference oscillator source is set to
INTernal
with automatic selection
enabled (
On)
when the counter is shipped from the factory or following the
SYSTem:SECure:IMMediate
command. Settings are stored in non-volatile
memory and are not changed after a reset (
*RST
) or instrument preset
(
SYSTem:PREset
or
Preset
key).