3 Input/Output Functions
Input/Output
Preset
Empty after Restore Input/Output Defaults. Survives shutdown/restart of analyzer application
(including power cycle)
Min
Freq: 0 Hz
Amptd: –1000 dBm
Max
Freq: 1 THz
Amptd: +1000 dBm
Initial S/W Revision
A.02.00
Modified at S/W Revision
A.14.00
Freq Ref In
Specifies the frequency reference as being the internal reference at the rear panel input labeled EXT REF
IN, a 1 pulse per second signal at the EXT REF IN input,, external reference or sensing the presence of a
signal at the EXT REF IN input.
When the frequency reference is set to internal, the internal 10 MHz reference is used even if an external
reference is connected.
When the frequency reference is set to external, the instrument will use the external reference. However, if
there is no external signal present, or it is not within the proper amplitude range, a condition error message
is generated. When the external signal becomes valid, the error is cleared.
When the frequency reference is set to Pulse, the instrument expects a 1 pulse per second signal at the
EXT REF IN input. The instrument uses this signal to adjust the frequency of the internal reference.
If Sense is selected, the instrument checks whether a signal is present at the external reference connector.
If it senses a signal within 5 ppm of the External Ref Freq (as set on the External Ref Freq softkey), it will
automatically switch to the external reference. If it senses a 1 pulse per second signal, it enters Pulse
mode, wherein the signal is used to adjust the internal reference. When no signal is present, it
automatically switches to the internal reference. No message is generated as the reference switches
between pulse, external and internal. The monitoring of the external reference occurs approximately on 1
millisecond intervals, and never occurs in the middle of a measurement acquisition, only at the end of the
measurement (end of the request).
If for any reason the instrument’s frequency reference is not able to obtain lock, Status bit 1 in the
Questionable Frequency register will be true and a condition error message is generated. When lock is
regained, Status bit 1 in the Questionable Frequency register will be cleared and the condition error will be
cleared.
If an external frequency reference is being used, you must enter the frequency of the external reference if it
is not exactly 10 MHz. The External Ref Freq key is provided for this purpose.
Key Path
Input/Output
Remote Command
[:SENSe]:ROSCillator:SOURce:TYPE INTernal | EXTernal | SENSe | PULSe
[:SENSe]:ROSCillator:SOURce:TYPE?
Dependencies
The PULSe parameter, and support of the 1 pps signal at the EXT REF IN input, are not available in
firmware prior to A.13.00. They are also not available in some model numbers. If not available, the
114
Sequence Analyzer User's & Programmer's Reference
Содержание E6650A EXF
Страница 34: ...1 About the Test Set Mouse and Keyboard Control 34 Sequence Analyzer User s Programmer s Reference...
Страница 94: ...2 Programming the Test Set Common Commands 94 Sequence Analyzer User s Programmer s Reference...
Страница 129: ...4 Mode Functions Undefined variable Primary ProductName Sequence Analyzer User s Programmer s Reference 129...
Страница 145: ...5 System Functions Undefined variable Primary ProductName Sequence Analyzer User s Programmer s Reference 145...
Страница 206: ...5 System Functions System 206 Sequence Analyzer User s Programmer s Reference...
Страница 214: ...6 List Sequence Measurements File File See File on page 146 214 Sequence Analyzer User s Programmer s Reference...
Страница 474: ...6 List Sequence Measurements Mode Mode See Mode on page 130 474 Sequence Analyzer User s Programmer s Reference...
Страница 478: ...6 List Sequence Measurements Print Print See Print on page 151 478 Sequence Analyzer User s Programmer s Reference...
Страница 642: ...6 List Sequence Measurements System System See System on page 152 642 Sequence Analyzer User s Programmer s Reference...