Rohde & Schwarz SCV8000E/R, Системное руководство

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Chapter 5 Operating
2104.6536.72 - 5.68 - E-1
3. Point to the right margin of the diagram with the mouse and set the last point.
Input mode will be terminated and you can now edit the curve as required (see the sec-
tion "Editing the characteristic").
Loading an existing characteristic curve
Instead of creating a characteristic curve from scratch, you can load existing curves into the
drawing level and edit them as required. There are three possibilities:
– Select Preset Curve in the contextual menu. A preset curve highlighted in the program
is loaded into the display level ( blue curve ). Now, using the Edit Read Curve contextual
entry, transfer the characteristic curve into the drawing level ( red curve ).
– Use the Curve Data xxx Read function to load the current characteristic curve from the
precorrection memory straight into the drawing level ( red curve ).
– Load an existing precorrection from a file using the Storage function from the Navigator
window for transmitter operation.
– In the RF Out > Precorrection menu window use the Restore Current Setting or Re-
store All Settings parameter to reactivate the original precorrection curve (factory set
precorrection) in the instrument. Then in the precorrector GUI use Parameters > Res-
can to update the display. The original precorrection curve is displayed.
Note You may have to fetch the read precorrection curve with the Show Read Curve contextual
function into the foreground so it can be viewed.
Editing a characteristic
Characteristics are edited based on the points they contain. Each point in the database con-
tains the following information: x value, y value, slope and locking of the slope. The number
of points is variable.
The characteristic is computed using one or more sectionally defined spline functions with
a specified start-point and end-point slope on the edges. The edges are considered to be
the right or left edge of the graphics as well as fixed points. A fixed point (recognizable by
a triangular symbol) "freezes" the slope of the curve. Like normal points, fixed points can
also be moved later on, but the slope due to the fixed point stays unchanged.
Existing points are edited directly . You can shift them with the mouse in the x and y direc-
tions (click and drag). Double-click to lock them (or to unlock them).
You can use the contextual menu to add and delete points and to lock and unlock their
slope. The procedure is as follows:
– Set Point:
1. Select the Set Point function.
2. Using the mouse, set a new point on the curve.
– Delete Point, Lock Point and Unlock Point:
1. Select the desired function.
2. Click on an existing point.
For fine setting of the characteristic, there is a navigator window available which can be
called up from the contextual menu. The navigator window can be used to set the point co-
ordinates and the slope (fixed points only) as numerical values. The procedure is as follows: