905
Common Measurement Functions
FREQ Channel
Zone Center
Zone Center appears as the top key in the Frequency menu in the Trace Zoom View of the Spectrum
Analyzer Mode.
Zone center allows you to change the frequency of the zone without changing the zone span. As the zone
center is changed, the center frequency of the lower window is changed. Note that the lower window will
not be updated to reflect the change unless it is selected as the active window.
The center frequency for the lower window is not limited by the selected start and stop frequencies in the
upper window. However, if the frequency span of the lower window is at all outside of the span for the
upper window, an orange arrow pointing left or right will be displayed at the left or right edge of the top
window.
Initial S/W Revision: A.07.01
Key Path: FREQ Channel
Remote Command: [:SENSe]:FREQuency:ZSPan:CENTer <frequency>
[:SENSe]:FREQuency:ZSPan:CENTer?
Example: :FREQ:ZSP:CENT 20 MHz
Notes: Min and Max values depend on the Hardware Options (5xx)
Dependencies: Only appears in the Zone Span View of the Swept SA measurement. If the
SCPI command is sent in other Views, an error is generated.
Couplings: • Center Frequency of lower window changes so that it is always the same
as Zone Center, and vice-versa
• Affected by Freq Offset exactly the same as is Center Frequency.
Preset: On entry to Zone Span, the Zone Center frequency is the same as the analyzer
Center Frequency. So if you do a Mode Preset and then immediately go into
Zone Span, Zone Center matches the Preset values listed in the table under the
Center Freq key description.
State Saved: Saved in instrument state
Min: Hardware dependent; Zone Span dependent. Zone Center cannot go so low as
to force Zone Left to be <0.
Max: The maximum Zone Center frequency is the same as the maximum analyzer
Center Frequency, which is basically the instrument maximum frequency – 5
Hz. See the table under the Center Freq key description.
Default Unit: Hz
Status Bits/OPC dependencies: Non-overlapped
Initial S/W Revision: Prior to A.02.00