G P I B C O M M A N D R E F E R E N C E
GPIB Command Reference
60
FPM-8200
C H A P T E R
4
Action
Sets a reference level in dBm.
Value range
+1.59 to −76.0 (Specification limits)
Notes
Measurements in dB are reported relative to this reference level.
See MODE:DB.
"+" is accepted but not necessary for positive values.
Front panel operation allows you to set the reference to the most recent measurement. (Press
dBm/W
and
dB
together). However the GPIB command allows you to set any arbitrary reference
level.
dBm is the log of the ratio of output power relative to one milliwatt. The calculation is:
Examples
REF 0
—
Set reference level to 0 dBm (1 mW).
Ref −18.24
—
Set reference level to −18.24 dBm (15 μW). This sequence accomplishes the same as
pressing
dBm/W
and
dB
:
Mode:dBm;Power?
—
Get most recent power measurement in dBm.
REF <power>
—
Using the result <power>, set the reference to the most recent power measure−
ment.
Action
Requests the reference level value.
Response
GPIB−standard nrf value, in the units currently defined. See MODE.
Note
Same function as pressing
dB
and
RECALL
together on the front panel.
Examples
REF?˙Response 0 means the reference level is 0 dBm.
Ref?˙Response −20 means the reference level is −20 dBm (10 μW).
Ref?˙Response 2.79565E−006 means the reference level is 2.79565 μW. Note the change in units.
See MODE?.
REF <nrf value>
Reference
C
OMMON
D
EVICE
D
EPENDENT
F
RONT
P
ANEL
REF?
Reference
C
OMMON
D
EVICE
D
EPENDENT
F
RONT
P
ANEL
output power in milliwatts
1 milliwatt
dBm = 10 log
Содержание FPM-8200
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