HP 53131A/132A 225 MHz Programming Manual page 259

Chapter 4 Command Reference
Introduction
Query Response
A sequence of ASCII-encoded bytes: ON or OFF
Comments
[:SENSe]:ROSCillator:EXTernal:FREQuency?
Queries the frequency value of the external reference oscillator.
Query Response
Comments
Query only.
[:SENSe]:ROSCillator:SOURce INTernal | EXTernal
Sets or queries current reference timebase.
INTernal indicates the timebase is the internal reference. EXTernal indicates the
signal at the external reference input (located on the rear panel of the Counter; Ref
In connector) is the reference timebase.
Query Response
A sequence of ASCII-encoded bytes: INT or EXT.
Programming Guide
*RST: ON
Use this command when [:SENS]:ROSC:SOUR EXT has been sent.
This value is unaffected by save/recall.
Numeric data transferred as ASCII bytes in <NR3> format with six
significant digits.
Range is 1E6 to 10E6.
Units are Hertz.
If the current reference timebase is external but the frequency is not known
(because it is not 1, 5, or 10 MHz and [:SENS]:ROSC:SOUR:AUTO is
OFF), Not a Number 9.91E37 is returned.
If the current reference timebase is internal, Not a Number 9.91E37 is
returned.
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