Markers
A marker is a tool for numerical readout of a stimulus value and value of the measured parameter in a specific point on the trace. You can activate up to 16 markers on each trace. See a trace with two markers in Figure 66.
The markers allow the user to perform the following tasks:
- Reading absolute values of a stimulus and a measured parameter in selected points on the trace;
- Reading relative values of a stimulus and a measured parameter related to the reference point;
- Search for specific points on the trace (minimum, maximum, target level, etc.);
- Determining trace parameters (statistics, bandwidth, etc.);
- Editing stimulus parameters using markers.
Figure 66
Markers can have the following indicators:
| 1 | symbol and number of the active marker on a trace, |
|---|---|
| | symbol and number of the inactive marker on a trace, |
| ▲ | symbol of the active marker on a stimulus axis, |
| | symbol of the inactive marker on a stimulus axis. |
The marker data field contains the marker number, stimulus value, and the measured parameter value. The number of the active marker is highlighted in inverse color.
The marker data field contents vary depending on the display format (rectangular or circular).
- In rectangular format, the marker shows the measurement parameter value plotted along Y-axis in the active format (See Table 8).
- In circular format, the marker shows two or three values listed in Table 23
Table 23Marker readings in circular formats
| Label | Marker Readings (Measurement Unit) | ||
|---|---|---|---|
| Reading 1 | Reading 2 | Reading 3 | |
| Smith (Lin) | Linear magnitude | Phase () | – |
| Smith (Log) | Logarithmic magnitude (dB) | Phase () | – |
| Smith (Re/Im) | Real part | Imaginary part | – |
| Smith (R + jX) | Resistance (Ω) | Reactance (Ω) | Equivalent capacitance or inductance (F/H) |
| Smith (G + jB) | Conductance (S) | Susceptance (S) | Equivalent capacitance or inductance (F/H) |
| Polar (Lin) | Linear magnitude | Phase () | – |
| Polar (Log) | Logarithmic magnitude (dB) | Phase () | – |
| Polar (Re/Im) | Real part | Imaginary part | – |
Marker Adding
| To enable a new marker, use the following softkeys: | ||
|---|---|---|
| Note | The new marker appears as the active marker in the middle of the stimulus axis. The marker stimulus value entry field activates. |
Marker Deleting
| To delete a marker, use the following softkeys: | ||
|---|---|---|
Marker Stimulus Value Setting
Before you set the marker stimulus value, you need to select the active marker. You can set the stimulus value by entering the numerical value from the keyboard, by arrows, or by dragging the marker using the mouse, or enabling the search function. Drag-and-drop operation is described in section 4.3.12. Marker search function is described in section 6.1.7.
| To set the marker stimulus value, use the following softkeys: | ||
|---|---|---|
Marker Activating
| . . . | To activate a marker by its number, use the following softkeys: | |
|---|---|---|
| To activate a marker from the list of markers, use the following softkeys: | ||
| Note | You can activate a marker by making a mouse click on it. |
Reference Marker Feature
Reference marker feature allows the user to view the data relative to the reference marker. Other marker readings are represented as delta relative to the reference marker. The reference marker shows the absolute data. The reference marker is indicated with ∆ symbol instead of a number (See Figure 67). Enabling of a reference marker turns all the other markers to relative display mode.
Figure 67
Reference marker can be indicated on the trace as follows:
| R | symbol of the active reference marker on a trace; |
|---|---|
| | symbol of the inactive reference marker on a trace. |
The reference marker displays the stimulus and measurement absolute values. All the rest of the markers display the relative values:
- stimulus value — difference between the absolute stimulus values of this marker and the reference marker;
- measured value — difference between the absolute measurement values of this marker and the reference marker.
| To enable/disable the reference marker, use the following softkeys: | ||
|---|---|---|
Marker Properties
Marker Coupling Feature
The marker coupling feature enables/disables dependence of the markers of the same numbers on different traces. If the feature is turned on, the coupled markers (markers with same numbers) will move along X-axis synchronously on all the traces. If the coupling feature is off, the position of the markers with same numbers along X-axis will be independent (See Figure 68).
Figure 68 Marker coupling feature
| To enable/disable the marker coupling feature, use the following softkeys: | ||
|---|---|---|
Marker Table
The marker table enables you to view the values of the markers of all the traces and all the channels (See Figure 69).
Figure 69 Marker table
| To show/hide the marker table, use the following softkeys: | ||
|---|---|---|
Marker Value Indication Capacity
By default, the marker stimulus values are displayed with 8 decimal digits and marker response values are displayed with 5 decimal digits. The user can change these settings.
| To set the marker value indication capacity, use the following softkeys: | ||
|---|---|---|
Multi Marker Data Display
If several overlapping traces are displayed in one graph, by default only active marker data are displayed on the screen. The user can enable display of the marker data of all the traces simultaneously. The markers of different traces will be distinguished by the color. Each marker will have same color with its trace.
| To enable/disable the multi marker data display, toggle the softkey: | ||
|---|---|---|
| Note | When multi marker data display is enabled, to avoid data overlapping on the screen, arrange the marker data on the screen (See section 6.1.6.5). |
Marker Data Arranging
By default, the marker data are displayed in the upper left corner of the screen. The user can rearrange the marker data display on the screen. The marker data position on the screen is described by two parameters: relative position on the X and Y axes, in percent. Zero percent is upper left corner, 100% is lower right corner. Marker data position for each trace is set separately. This allows the user to avoid data overlapping on the screen.
| To arrange the marker data on the screen, enter the relative position on the X and Y axes, using the following softkeys: | ||
|---|---|---|
| Note | You can also drag-and-drop the marker data by the mouse. |
Marker Data Alignment
By default, the marker data are displayed independently for each trace. The user can align the marker data display on the screen. The alignment deactivates the independent marker data layout. In this case, the relative position on the X and Y axes is valid only for the first trace. The marker data of the other traces become aligned relatively to the first trace. Two types of alignment are available:
- Vertical – marker data of different traces are displayed one under another;
- Horizontal – marker data of different traces are displayed in line.
| To set the marker data alignment, use the following softkeys: | ||
|---|---|---|
Memory Trace Value Display
By default, the marker values of the data traces (not memory traces) are displayed on the screen. The user can enable the display of memory trace maker values, if a memory trace is available.
| To enable/disable the display of memory trace marker values, toggle the softkey: | ||
|---|---|---|
Marker Position Search Functions
Marker position search function enables you to find on a trace the following values:
- maximum value;
- minimum value;
- peak value;
- target level.
Search for Maximum and Minimum
Maximum and minimum search functions enable you to determine the maximum and minimum values of the measured parameter and move the marker to these positions on the trace (See Figure 70).
Figure 70 Maximum and minimum search
| To find the maximum or minimum values on a trace, use the following softkeys: | ||
|---|---|---|
| Note | Before you start maximum or minimum search, first activate the marker. |
Search for Peak
Peak search function enables you to determine the peak value of the measured parameter and move the marker to this position on the trace (See Figure 71).
Peak is a local extreme of the trace.
Peak is called positive if the value in the peak is greater than the values of the adjacent points.
Peak is called negative if the value in the peak is smaller than the values of the adjacent points.
Peak excursion is the smallest of the absolute differences between the response values in the peak point and the two adjoining peaks of the opposite polarity.
Figure 71 Positive and negative peaks
The peak search is executed only for the peaks meeting the following conditions:
- The peaks must have the polarity (positive, negative, or both) specified by the user;
- The peaks must have the peak deviation not less than the value assigned by the user.
The following options of the peak search are available:
- Search for nearest peak;
- Search for greatest peak;
- Search for left peak;
- Search for right peak.
The nearest peak is a peak, which is located most near to the current position of the marker along the stimulus axis.
The greatest peak is a peak with maximum or minimum value, depending on the current polarity settings of the peak.
| Note | The search for the greatest peak is deferent from the search for maximum or minimum as the peak cannot be located in the limiting points of the trace even if these points have maximum or minimum values. | |
|---|---|---|
| To set the polarity of the peak, use the following softkeys: | ||
| To enter the peak excursion value, use the following softkeys: | ||
| To activate the nearest peak search, use the following softkeys: | ||
| To activate the greatest peak search, use the following softkeys: | ||
| To activate the left peak search, use the following softkeys: | ||
| To activate the left peak search, use the following softkeys: | ||
| Note | Before you start maximum or minimum search, first activate the marker. |
Search for Target Level
Target level search function enables you to locate the marker with the given level of the measured parameter (See Figure 72).
The trace can have two types of transition in the points where the target level crosses the trace:
- transition type is positive if the function derivative (trace slope) is positive at the intersection point with the target level;
- transition type is negative if the function derivative (trace slope) is negative at the intersection point with the target level.
Figure 72 Target level search
The target level search is executed only for the intersection points, which have the specific transition polarity selected by the user (positive, negative, or both).
The following options of the target level search are available:
- Search for nearest target;
- Search for left target;
- Search for right target.
| To set the transition polarity, use the following softkeys: | ||
|---|---|---|
| To enter the target level value, use the following softkeys: | ||
| To activate the nearest target search, use the following softkeys: | ||
| To activate the left target search, use the following softkeys: | ||
| To activate the right target search, use the following softkeys: | ||
| To enable/disable target level indication on the screen, use the following softkeys: | ||
| Note | Before you start maximum or minimum search, first activate the marker. |
Search Tracking
The marker position search function by default can be initiated by any search key pressing. Search tracking mode allows you to perform continuous marker position search, until this mode is disabled.
| To enable/disable search tracking mode, use the following softkeys: | ||
|---|---|---|
Search Range
The user can set the search range for the marker position search by setting the stimulus limits. This function involves the following additional features:
- search range coupling, which allows the user to define the same search range for all the traces of a channel;
- vertical line indication of the search range limits.
| To enable/disable the search range, use the following softkeys: | ||
|---|---|---|
| To set the search range limits, use the following softkeys: | ||
| To enable/disable search range coupling, use the following softkeys: | ||
| To enable/disable search range limits indication, use the following softkeys: |
Marker Math Functions
Marker math functions are the functions, which use markers for calculating of various trace characteristics. Four marker math functions are available:
- Statistics;
- Bandwidth Search;
- Flatness;
- RF Filter.
Trace Statistics
The trace statistics feature allows the user to determine and view such trace parameters as mean, standard deviation, and peak-to-peak. The trace statistics range can be defined by two markers (See Figure 73).
Statistic Range: ON
Statistic Range: OFF
Figure 73 Trace statistics
Table 24Statistics parameters
| Symbol | Definition | Formula |
|---|---|---|
| mean | Arithmetic mean | |
| s.dev | Standard deviation | |
| p-p | Peak-to-Peak: difference between the maximum and minimum values | Max – Min |
| To enable/disable trace statistics function, use the following softkeys: | ||
|---|---|---|
| To enable/disable trace statistics range, use the following softkeys: | ||
| To set the start/stop markers of the statistics range, use the following softkeys: |
Bandwidth Search
The bandwidth search function allows the user to determine and view the following parameters of a passband or a stopband: bandwidth, center frequency, lower frequency, higher frequency, Q value, and insertion loss (See Figure 74). In the figure, F1 and F2 are the lower and higher cutoff frequencies of the band respectively.
The bandwidth search is executed from the reference point. The user can select as reference point the active marker or the maximum of the trace. The bandwidth search function determines the lower and higher cutoff frequencies, which are apart from the reference point response by bandwidth value defined by the user (usually –3 dB).
Passband
Bandwidth Value
F2
F1
Stopband
Bandwidth Value
F2
F1
Figure 74 Bandwidth search
Table 25 Bandwidth parameters
| Parameter Description | Symbol | Definition | Formula |
|---|---|---|---|
| Bandwidth | BW | The difference between the higher and lower cutoff frequencies | F2 – F1 |
| Center Frequency | cent | The midpoint between the higher and lower cutoff frequencies | (F1+F2)/2 |
| Lower Cutoff Frequency | low | The lower frequency point of the intersection of the bandwidth cutoff level and the trace | F1 |
| Higher Cutoff Frequency | high | The higher frequency point of the intersection of the bandwidth cutoff level and the trace | F2 |
| Quality Factor | Q | The ratio of the center frequency to the bandwidth | Cent/BW |
| Loss | loss | The trace measured value in the reference point of the bandwidth search | - |
| To enable/disable bandwidth search function, use the following softkeys: | ||
|---|---|---|
| Set the bandwidth search type by softkeys: | ||
| To set the search reference point, use the following softkeys: | ||
| To enter the bandwidth value, use the following softkeys: |
Flatness
The flatness search function allows the user to determine and view the following trace parameters: gain, slope, and flatness. The user sets two markers to specify the flatness search range (See Figure 75).
Flatness Search Rage
Δ¯max
Δ+max
Flatness = Δ+max + Δ¯max
Figure 75 Flatness search
Table 26 Flatness parameters
| Parameter Description | Symbol | Definition |
|---|---|---|
| Gain | gain | Marker 1 value |
| Slope | slope | Difference between marker 2 and marker 1 values. |
| Flatness | flatness | Sum of “positive” and “negative” peaks of the trace, which are measured from the line connecting marker 1 and marker 2 (See Figure 75). |
| To enable/disable the flatness search function, use the following softkeys: | ||
|---|---|---|
| To select the markers specifying the flatness search range, use softkeys: |
RF Filter Statistics
The RF filter statistics function allows the user to determine and view the following filter parameters: loss, peak-to-peak in a passband, and rejection in a stopband. The passband is specified by the first pair of markers, the stopband is specified by the second pair of markers (See Figure 76).
Stopband
Passband
Figure 76 RF filter statistics
Table 27 RF filter statistics parameters
| Parameter Description | Symbol | Definition |
|---|---|---|
| Loss in passband | loss | Minimum value in the passband |
| Peak-to-peak in passband | p-p | Difference between maximum and minimum in the passband |
| Reject | rej | Difference between maximum in stopband and minimum in passband |
| To enable/disable the RF filter statistics function, use the following softkeys: | ||
|---|---|---|
| To select the markers specifying the passband, use the following softkeys: | ||
| To select the markers specifying the stopband, use the following softkeys: |
Marker Functions
Using the current position of a marker you can perform settings of the following parameters:
- Stimulus start;
- Stimulus stop;
- Stimulus center;
- Reference level;
- Electrical delay.
Before performing the settings, first activate the marker.
| To set the stimulus start, use the following softkeys: | ||
|---|---|---|
| To set the stimulus stop, use the following softkeys: | ||
| To set the stimulus center, use the following softkeys: | ||
| To set the reference level, use the following softkeys: | ||
| To set the electrical delay, use the following softkeys: | ||
| To set reference marker to the active marker point, use the following softkeys: |