Agilent Technologies 53220A User Manual page 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 ) 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).
53220A/53230A User's Guide 67