Keysight Truevolt Serie Mode D'emploi page 222

CALCulate:SCALe:DBM:REFerence {<reference>|MIN|MAX|DEF}
CALCulate:SCALe:DBM:REFerence? [{MIN|MAX|DEF}]
Selects the reference resistance for converting voltage measurements to dBm. This reference value
affects the dBm and dB scaling functions.
50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500, 600, 800, 900, 1000, 1200 or
8000 Ω. Default: 600.
Enable dBm scaling with a reference resistance of 300 Ω:
CALC:SCAL:DBM:REF 300
CALC:SCAL:FUNC DBM
CALC:SCAL:STAT ON
The instrument sets the reference value to its default value after a Factory Reset (*RST), an Instru-
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ment Preset (SYSTem:PRESet), or a change in measurement function.
CALCulate:SCALe:FUNCtion {DB|DBM|PCT|SCALe}
CALCulate:SCALe:FUNCtion?
Selects the operation performed by the scaling function.
Parameter
{DB|DBM|PCT|SCALe}
Enable the DB scaling function referenced to the next measurement taken:
CALC:SCAL:FUNC DB
CALC:SCAL:STAT ON
The PCT and SCALe functions apply only to the 34465A and 34470A.
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DB performs a relative dB computation. The result is the difference between the input signal and the
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stored DB relative value reference (CALCulate:SCALe:DB:REFerence), with both values converted to
dBm (dB = measurement in dBm – relative value in dBm). For the dB function, the reference value can
be automatically selected using the first measurement converted to dBm as the reference value (see
CALCulate:SCALe:REFerence:AUTO), or it can be specified by CALCulate:SCALe:DB:REFerence. dB
scaling applies to ACV and DCV measurements only.
DBM performs a dBM computation. The result is logarithmic and is based on a calculation of power
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delivered to a reference resistance (CALCulate:SCALe:DBM:REFerence), relative to 1 milliwatt.
(dBm = 10 × log 10 (measurement 2 / reference resistance / 1 mW)). dBm scaling applies to ACV and
DCV measurements only.
Keysight Truevolt Series Operating and Service Guide
Parameter
Typical Return
DB, DBM, PCT, or SCALe
SCPI Programming Reference
Typical Return
+3.00000000E+02
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