893
BW
Coupling Auto Rules:
The Auto Rules for the
VBW:3dB RBW function are as follows:
First, we go through the following list and find the lowest numbered detector being used on any active
traces (traces for which Update is On):
Peak
Normal
Average
Sample
Negative Peak
EMI Average
Quasi Peak
RMS Average
Use that detector to pick the ratio based on the following criteria:
1. If the detector is Peak and the EMC Standard is set to either CISPR or MIL, use 10.0
(we use wide
VBWs to capture peak levels accurately).
2. Otherwise, if the detector is
Negative Peak, use 1.0 (in the Negative Peak case, there are no known
significant use models so we use a medium ratio).
3. Otherwise, if the detector is
Normal, use 1.0.
4. Otherwise, if the detector is
Average, and the span in nonzero, use 0.1. The use of a small ratio in
Average detection is desirable because of its effect on the sweep time equations. The VBW filter is
Example BAND:VID:RAT 2
BAND:VID:RAT?
BAND:VID:RAT:AUTO 0
BAND:VID:RAT:AUTO?
Notes The values shown in this table reflect the conditions after a Mode Preset.
Couplings See “Coupling Auto Rules:” on page 893
Preset 1
ON
State Saved Saved in Instrument State
Min 0.00001
Max 3000000
Initial S/W Revision Prior to A.02.00
Modified at S/W Revision A.02.00