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).

Tracking Markers

Tracking markers measure the position and magnitude at any sample point on a single-valued waveform. Tracking markers can be placed on Waveform, Freq-Mag, Phase, GrpDelay, Time-Ohms, Time-Volts, and Time-% waveform content windows. When a tracking marker is placed on a Freq-Mag, Phase, and GrpDelay window, it appears on the same x position on all three of these windows. In TDR mode, a tracking marker assigned to a Time-Ohms, Time-Volts, and Time-% window does not appear on the other Time windows. Freq-Mag, Phase, and GrpDelay windows are displayed for TDR Mode's S-parameters and when using the FFT math function (other than an FFT that is defined as Linear Magnitude). Time-Ohms, Time-Volts, and Time-% windows are displayed for TDR Mode's T-parameters.

Manual Line Markers

Manual line markers should be used on eye diagrams (multi-valued waveforms). Manual line markers measure the position or magnitude of any location on the display and not just a point on a waveform. Although manual line markers can be used in Scope and TDR mode (in the Waveform, Time-Ohms, Time-Volts, and Time-% waveform content windows only) they are of minimal value. Instead, use tracking markers. Manual line markers can never be placed on Freq-Mag, Phase, or GrpDelay waveform content windows in any measurement mode.

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 CHAN1A  //  Assign marker to Channel 1A 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 CHAN1A  //  Assign marker to Channel 1A 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

Example Command Sequence for Tracking Marker on TDR Mode S-Parameter Waveforms

This command sequence assumes that the FlexDCA is in TDR mode and that the Magnitude, Phase, and Group Delay S-parameter graphs are displayed for two DUTs.

  //  Configure Tracking Marker Pair 1
:MARKer:Y1A:STATe TRACk  //  Turn on tracking marker 1
:MARKer:Y1A:SOURce:TYPE SPARameter  //  Select S-Parameter Waveform
:MARKer:Y1A:SOURce:DUT DUT1  //  Select Response of DUT 1
:MARKer:Y1A:SOURce:SPARameter S2_1  //  Select S-Parameter S21
:MARKer:X1:POSition 6.0E+9  //  Position marker to 6.0 GHz
  //  Configure Tracking Marker Pair 2
:MARKer:Y2A:STATe TRACk  //  Turn on tracking marker 2
:MARKer:Y2A:SOURce:TYPE SPARameter  //  Select S-Parameter Waveform
:MARKer:Y2A:SOURce:DUT DUT2  //  Select Response of DUT 2
:MARKer:Y2A:SOURce:SPARameter S2_1  //  Select S-Parameter S21
:MARKer:X2:POSition 6.790E+9  //  Position marker to 6.0 GHz
:MARKer:REFerence X1  //  Reference for delta measurements
  //  Return Marker Table Measurements for Tracking Marker 2
:MEASure:MARKer:DX2?  //  Return ΔPosition
:MEASure:MARKer:Y1A?  //  Return Magnitude
:MEASure:MARKer:Y1B?  //  Return Phase
:MEASure:MARKer:Y1C?  //  Return Delay
:MEASure:MARKer:Y2A?  //  Return Magnitude
:MEASure:MARKer:Y2B?  //  Return Phase
:MEASure:MARKer:Y2C?  //  Return Delay

Tracking Markers

When using tracking markers in Oscilloscope Mode, turn pattern lock on if a multi-valued waveform is displayed.In Eye/Mask Mode, turn Pattern lock on. If Acquire Entire Pattern is selected, turn Wrap Waveform off. In TDR/TDT Mode, assign the marker to a channel, T-domain, or S-parameter waveform.

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
	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, Memory, or TDR/TDT Mode's T-Domain 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 TDR/TDT Mode's S-Parameter Waveforms
Select Source Waveform	:MARKer:X{1:4}:SOURce	—
Select TYPE	:MARKer:X{1:4}:SOURce:TYPE SPARameter	—
Select DUT	:MARKer:X{1:4}:SOURce:DUT	—
Select S-Parameter	:MARKer:X{1:4}:SOURce:SPARameter	—
Query Marker Measurements
Channel or T-Domain Waveforms	:MEASure:MARKer:DX{1:4}? :MEASure:MARKer:IDX{1:4}? :MEASure:MARKer:DY{1:4}{A:C}? :MEASure:MARKer:Y{1:4}{A:C}?
S-Parameter Waveforms	:MEASure:MARKer:DX{1:4}? :MEASure:MARKer:IDX{1:4}? :MEASure:MARKer:DY{1:4}{A:C}? :MEASure:MARKer:Y{1:4}{A:C}?	—
Show or Hide Δ Measurments in Marker Table	:DISPlay:MARKer:DELTas

Markers on T-Domain Parameters and S-Parameters

Tracking markers can be placed on both T-domain parameters and 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 :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): Freq-Mag, Phase, and GrpDelay. For example, consider a marker placed on an S21 waveform that is displayed on a Freq-Mag window. The marker will automatically appear on the S21 waveform in both the Phase and GrpDelay windows, if they are displayed. Moving the marker's horizontal position on one trace, moves its position on all three waveforms. However, separate markers are required for identical T-domain parameters viewed on Time-Ohms, Time-Volts, and Time-% content windows.

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. For non-spectral waveforms this is determined by Acquire Entire Pattern Setting (ACQuire:EPATtern) as described in the following table. 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

Acquire Entire Pattern Setting	Marker X-Axis Position	Marker Y-Axis Value
Non-Spectral Waveforms
Enabled	any time position	interpolated
Disabled	restricted to sampling- point position	nearest sampling- point value
Spectral Waveforms (such as created by the FFT function)
Enabled	always restricted to sampling-point position	always nearest sampling-point value
Disabled