6 Input/Output
6.2 Input
Example Set the attenuation for the current I probe type to 100.00:1:
:CORR:IQ:I:ATT 20 dB
Min/Max -60 dB /+80 dB
Offset
Some active probes have DC offset capability. When one of these probes is
connected, this control will be visible. The signal is adjusted for the DC offset before
entering the instrument's port. This allows for removal of a DC offset before
reaching the instrument's input port voltage limits. For example, a signal that varies
1 V peak-to-peak with a DC offset equal to the instrument's max input voltage
would exceed the input limits of the instrument for half its cycle. Removing the DC
offset allows the instrument to correctly process the entire signal.
Remote
Command
:INPut:OFFSet:I <voltage>
:INPut:OFFSet:I?
Example Remove a DC offset of -0.5 V from the I channel input:
:INP:OFFS:I -0.5
Notes Only some probe types support Offset. For those that do, each probe type has its own Offset setting. As
probes are changed, the Offset value will reflect the new probe's setting. Changing Offset affects only
the current probe type's setting and leaves all others unchanged
Preset 0 V
State Saved Saved with probe calibration data. Survives power cycle and is not affected by Preset or Restore
Min/Max -18 V/+18 V
Coupling
Some probe types allow coupling to reject low frequencies. This filters out the DC
component of a signal that is composed of a DC bias plus some AC signal. This
control is visible only for probe types that have this capability.
Remote
Command
:INPut:COUPling:I DC | LFR1 | LFR2
:INPut:COUPling:I?
Example Turn off low frequency rejection on the I channel, allowing signals down to DC:
:INP:COUP:I DC
Turn on low frequency rejection on the I channel for frequencies lower than 1.7 Hz:
:INP:COUP:I LFR1
Turn on low frequency rejection on the I channel for frequencies lower than 0.14 Hz:
:INP:COUP:I LFR2
Notes Only some probe types support Coupling. For those that do, each probe type has its own Coupling
setting. As probes are changed, the Coupling value will reflect the new probe's setting. Changing
Vector Modulation Analyzer Mode User's &Programmer's Reference 2172