Rohde & Schwarz R&S UPP, Руководство пользователя

Страница: 154 / 938

Manual Operation
R&S
®
UPP
138 User Manual 1411.1055.32 ─ 10
This is done differently depending on the selected mode:
●
In Edit mode , the newly entered numeric value is adopted and set together with
the selected unit.
●
In Direct mode , the physical value (number with the previously selected unit) is
converted to the newly selected unit and adopted as the new numeric value.
After finishing entering a value or even if no value has been changed, the softkeys can
be used to change the unit in any highlighted numeric field. In this case, the physical
value remains unchanged (as in the Direct mode); however, the value displayed in the
entry field is adapted automatically to the changed unit. This function allows numeric
values to be "converted" to other units very easily.
4.7.9.4 Information on Using Reference Values when Entering Values
The audio analyzer allows reference values in various places. These reference values
are used as a basis for settings for other parameters.
The example below explains these interdependencies:
A reference voltage ("Ref Voltage") can be set in the "Generator Config" panel. The
actual output voltage is set in the "Generator Function" panel where the unit is dBr, i.e.
it is possible to enter the output voltage in dB relative to this reference value.
This method is particularly useful if, e.g. with an A/D converter, the clipping level has
been determined and other measurements (frequency response, THD+N, etc.) have to
be performed using test signals which are a certain dB value (defined in the test speci-
fications) below this full-scale level.
It should be noted, however, that the maximum values of the R&S UPP cannot be
exceeded, both for system reasons and due to the "Max Voltage" setting.
If the maximum output voltage is exceeded by increasing the reference value, the ref-
erence-based value in the "Voltage" field of the "Generator
Function" panel is automati-
cally reduced. In the following example, the maximum output voltage of 20 V forms the
limit. The setting of the reference value to 100 V leads to a reduction of the value in the
lower window.
Settings in the Panels