Instrument Function > RF Block > RF Measurement > NRP-Z Power Analysis > Setup Trace
Setup Trace

The measurement data can be current (sensor trace) or stored trace data, either in a file (reference trace) or in a temporary memory (hold trace). Up to four traces can be indicated at one time. On connection, the sensors are automatically detected and assigned to a trace. By default, connected sensors are assigned to the traces in ascending order, that means sensor 1 to trace 1, sensor 2 to trace 2, etc. If the default trace is already used, the sensor has to be assigned manually in the trace dialog.

With the reference and hold traces, you can compare traces. Assign a reference curve to one trace and your measured values to a second one, and switch on the display. This feature provides to compare results directly in the graph, or to show deviations in a graph by using the "Mathematics" function.

Example

The current single measurement of sensor 2 which is assigned to trace 2 is used as reference trace.

  1. Select "Trace 2" with "Indication 2" = NRP-Zx.

  2. Select "Save To Ref".

  3. Select "Trace 1" and "Indication Ref.".

  4. Select "Diagram".

    The R&S SMA indicates two identical traces.

  5. Select "Start single".

    Triggers a new measurement cycle with sensor 2. You can compare the resulting measurement trace with the former measurement, which is displayed as reference trace.

Trace

Selects the index of the trace. The source for the trace data is selected below. The trace color for each of the four possible traces is preset but can be changed.

Remote command: 

n.a.

In remote control, the trace is selected by the suffix of keyword TRACe.

 
Indication - Power Analysis

Selects the source for the trace data.

All available sensors, a reference trace if stored and the hold option are indicated in the selection menu. This menu is automatically updated if a sensor is connected or disconnected. By default, connected sensors are assigned to the traces in ascending order, that means sensor 1 to trace 1, sensor 2 to trace 2, etc. If the default trace is already used, the sensor has to be assigned manually in the trace dialog.

The selection is indicated on the trace button in the measurement diagram.

"Off"

No source is selected, the trace is not indicated.

Remote command: 

 

"2 - NRP-Zxx"

The current measurement results of the selected power sensor are the source for the trace data. The index at the beginning of the sensor name indicates the used connector, for example "2" indicates that the sensor is connected via a USB interface. The data is either continuously updated (continuous measurement) or represents a single measurement cycle (single measurement).

Remote command: 

 

"Ref"

Selects the reference trace. The reference trace is a static trace that was stored in a file and can be recalled.

It is possible to store one reference trace at a time.

Remote command: 

 

"Hold"

Freezes the current trace data. The hold trace is a temporary trace that is available until the NRP power analysis is finished. Freezing the trace of a sensor in one trace and displaying the measurement values of the same sensor in another trace allows fast comparison between measurements.

Remote command: 

n.a.

 

Save to Ref - Trace Power Analysis

Saves the selected trace as reference trace. One reference trace is available at a time.

Remote command: 
 
Define Reference - Trace Power Analysis

Opens a dialog for defining a linear reference curve.

To define the reference curve, set the coordinates of "Point A" and "Point B".

The reference curve is determined by two value pairs in the cartesian coordinates of the "NRP-Z Analysis" diagram. Depending on the measurement mode, the following values are required:

The reference curve consists of a certain number of coordinate points, calculated by the number of steps + 1. The first coordinate point starts at Min, and Max is the last. "Step", "Min" and "Max" are determined in the configuration dialog, see "Configure Measurement".

Tip: You can assign the X and Y coordinates of the markers automatically in marker view. By selecting "Fill Point", the function automatically reads the X and Y coordinates from the trace data and derives the intersection point of the selected marker and the trace curve.

Mathematics - Trace Power Analysis

Activates the mathematic function.

The function enables you to determine the deviation of two test series, either of measurement traces, or also of traces that contain math results or stored reference curves. That means you can also assign a math result to an operand for further calculation. Various nested computation steps are possible.

The math operation follows the formula:

T<ch>result = T<ch> Operand1 - T<ch>Operand2

How to proceed:

Determine T<ch> Operand1 in the entry field next to "Tx", and then select T<ch>Operand2 in the second entry field right to it.

The result ("T<ch>result") is assigned to the above selected "Trace". If switched on, the graph shows the resulting curve.

Note:

Depending on the type of trace, the instrument automatically sets the appropriate unit on the y-axis:
  • "dBm" if it shows only measurement traces.
  • "dB" for purely mathematical curves.
  • "dB/dBm" ratio scale for mixed display, that means measurements and mathematical curves.
Example: 
Example of a nested calculation.
  • T1 shows the result of the subtraction of the trace ("Trace 1"), and the reference curve.
  • Trace2 subtracts Ref from T1.

    That illustrates the nested calculation, since T1 covers already a math operation.
    Note: "(Ind.)" denotes the currently selected trace.
Remote command: 
 
Color - Trace Power Analysis

Selects the color of the trace.

Remote command: 
 
Diagram.. - Power Analysis

Returns to the "NRP-Z Analysis Diagram".

 


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