:MARKer Subsystem

The Marker (MARKer) subsystem commands control up to four tracking markers and eight manual line markers. In almost all situations, use tracking markers which are designed for single-valued waveforms. Manual line markers are designed for Eye diagrams (multi-valued waveforms).

Example Command Sequence

This example illustrates how to use all of the marker related commands and, as a result, is not presented as a best measurement practice. The example uses a tracking marker , manual line X marker, and manual line Y marker. Because a tracking marker is used, the waveforms must be single-valued. You could also turn on two tracking markers and read the delta values between them.

                  //  Configure Manual Line Marker X1
:MARKer:X1:STATe MANual  //  Turn on marker
:MARKer:X1:SOURce CHAN1_1  //  Assign marker to connection 1 channel 1 waveform
:MARKer:X1:POSition 80E-12  //  Position marker to 80 ps
                
                  //  Configure Manual Line Marker Y1
:MARKer:Y1A:STATe MANual  //  Turn on Y manual line marker 1.
:MARKer:Y1A:SOURce CHAN1_1  //  Assign marker to connection 1 channel 1 waveform
:MARKer:Y1A:POSition 120E-3  //  Position marker to 120 mv
:MARKer:REFerence X1  //  Set markers X1 and Y1 as the reference
                
                  //  Configure Tracking Marker Pair 2
:MARKer:Y2:STATe TRACking  //  Turn on marker
:MARKer:X2:SOURce FUNCtion3  //  Assign marker to FUNCtion 3 waveform
:MARKer:X2:POSition 200E-12  //  Position marker on screen
                
                  //  Return Marker Table Measurements for Tracking Marker 2
:MEASure:MARKer:DX2?  //  Return ΔPosition
                
:MEASure:MARKer:IDX2?  //  Return inverse of ΔPosition
                
:MEASure:MARKer:DY2?  //  Return ΔMagnitude
                
:MEASure:MARKer:Y2?  //  Return Y2 Magnitude

Tracking Markers

Turning on a tracking marker prevents the use of the associated manual line markers as shown in the following table. This will not be much of an issue as you will use tracking markers for almost all of your marker needs. However, if you want to use a manual line marker always first make sure that the marker (1, 2, 3, or 4) is not already defined as a tracking marker. For example:

:MARKer:Y1A:STATe OFF
:MARKer:X1:STATe MANual
:MARKer:Y1A:STATe MANual

Tracking Markers and
Associated Manual-Line Markers
Tracking Marker	Consumed Manual-Line Markers
Tracking Marker	X Marker	Y Marker
1	X1	Y1
2	X2	Y2
3	X3	Y3
4	X4	Y4

Marker Tasks

The following table shows the commands and queries used when working with markers. The difference between any two markers can be queried, even if the markers use different source waveforms. For detailed information including syntax, refer to the topics for the individual commands.

Commands for Marker Tasks
Task	Tracking Markers	Manual-Line Markers
Turn Markers On and Off	`:MARKer:Y{1:4}{A:C}:STATe TRACk`	`:MARKer:X{1:4}:STATe MANual` `:MARKer:Y{1:4}{A:C}:STATe MANual`
Position a Marker	`:MARKer:X{1:4}:POSition`	`:MARKer:X{1:4}:POSition` `:MARKer:Y{1:4}{A:C}:POSition`
Set the Reference Marker	`:MARKer:REFerence`
For Channel, Function, or Memory Waveforms
Select Source Waveform	`:MARKer:X{1:4}:SOURce`	`:MARKer:X{1:4}:SOURce` `:MARKer:Y{1:4}{A:C}:SOURce`
Select TYPE	`:MARKer:X{1:4}:SOURce:TYPE WAVeform`
For S-Parameter Waveforms
Select Source Waveform	`:MARKer:X{1:4}:SOURce`	—
Select TYPE	`:MARKer:X{1:4}:SOURce:TYPE SPARameter`	—
Select DUT	`:MARKer:X:SOURce:DUT`	—
Select S-Parameter	`:MARKer:X:SOURce:SPARameter`	—
Query Marker Measurements
Channel Waveforms	`:MEASure:MARKer:DX?` `:MEASure:MARKer:IDX?` `:MEASure:MARKer:DY?` `:MEASure:MARKer:Y{1:4}{A:C}?`
S-Parameter Waveforms	`:MEASure:MARKer:DX?` `:MEASure:MARKer:IDX?` `:MEASure:MARKer:DY?` `:MEASure:MARKer:Y?`	—
Show or Hide Δ Measurements in Marker Table	`:DISPlay:MARKer:DELTas`

Markers on S-Parameters

Tracking markers can be placed on S-parameters. However, manual line-markers cannot be placed on S-parameters. The parameter waveform is selected for a marker by using the TRACe argument with the :MARKer:X:SOURce and :MARKer:Y:SOURce commands. For example,

:MARKer:X2:SOURce TRACe9

The parameter is assigned to a trace number when you create the trace using :NETWorks:TRACe subsystem commands.

Because S-parameters contain magnitude, phase, and delay information, a tracking marker that is placed on an S-parameter waveform will appear at the same X-axis position on all three content windows (if displayed): Decibels (Hz), Degrees (Hz), and Seconds (Hz). For example, consider a marker placed on an S21 waveform that is displayed on a Decibels (Hz) window. The marker will automatically appear on the S21 waveform in both the Degrees (Hz) and Seconds (Hz) windows, if they are displayed. Moving the marker's horizontal position on one trace, moves its position on all three waveforms.

Markers and Waveform Sampling Points

When positioning a tracking marker between waveform sampling points, the marker's time position and associated y-axis value may be restricted. Because there is normally an abundance of waveform sampling points on screen, you may seldom notice that a marker is restricted to specific positions and values.

Tracking Marker Positions and Values Versus Pattern Acquisition
Marker X-Axis Position	Marker Y-Axis Value
Non-Spectral Waveforms
restricted to sampling- point position	nearest sampling- point value
Spectral Waveforms (such as created by the FFT function)
always restricted to sampling-point position	always nearest sampling-point value