Fact 8. Learn Waveform Windows

Waveforms are displayed in one of eight different types of content windows depending on the type of waveform. The following table lists these windows along with the waveform types that they can contain. Before FlexDCA revision A.03.00, the only available content window type was Waveform and it defines the Y-axis in linear amplitude units (V or W) and the X-axis in time. All content windows can show multiple waveforms of the same type. However, in the Waveform content window, multiple waveforms can each have different Y-axis scaling. In all other content windows, multiple waveforms displayed within the same window have the same scaling.

Content Window Types

Content Window Title	Availability in Instrument Mode				Waveform Types	Number of Available Windows		SCPI Command Used to Assign Waveform to Content Window	Description
	Scope	Eye	TDR	Jitter		Via Front Panel	Program- matically
Waveform	♦	♦	♦		Channels Differential Channels Most Functions Waveform Memory Eye/Mask Memory	1	1	None	This is the default window for most waveforms. Y-Axis: Volts or Watts (linear scale) X-Axis: seconds
Freq-Mag	♦	♦	♦		Output of FFT math function	1	4	:FUNCtion:CWINdow MAGNitude	Y-Axis: dBV or dBm (logarithmic scale). X-Axis: seconds or Hertz. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
					TDR/TDT S-Parameters	4	4	:TRACe:CWINdow MAGNitude
GrpDelay	♦	♦	♦		Output of FFT math function	1	4	:FUNCtion:CWINdow GDELay	Y-Axis: seconds X-Axis: Hertz. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
					TDR/TDT S-Parameters	4	4	:TRACe:CWINdow GDELay
Phase	♦	♦	♦		Output of FFT math function	1	4	:FUNCtion:CWINdow PHASe	Y-Axis: phase (°) X-Axis: Hertz. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
					TDR/TDT S-Parameters	4	4	:TRACe:CWINdow PHASe
Time-Ohms			♦		TDR/TDT T-Domain Responses	4	4	:TRACe:CWINdow TOHMs	Y-Axis: Ohms X-Axis: Time. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
Time-Volts			♦		TDR/TDT T-Domain Responses	4	4	:TRACe:CWINdow TVOLts	Y-Axis: Volts X-Axis: Time. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
Time-%			♦		TDR/TDT T-Domain Responses	4	4	:TRACe:CWINdow TPERcent	Y-Axis: % X-Axis: Time. Use the GRAPh subsystem commands to autoscale, position, and scale waveforms.
Graphs				♦	Channel and Jitter Data Memory	—	—	None	Used for display of all Jitter Mode graphs.

Assigning Waveforms to Content Windows

When created, waveforms are automatically displayed in content window number 1 for the correct type. As shown in the above table, multiple content windows (up to four total) are available for some types. To move a waveform to an additional content window use the SCPI commands shown in the table. If the additional content window does not exist, it will be automatically created.

Axis Scaling

The :TIMebase, :GRAPh, and :TRACe subsystems are used to create and scale content windows and their waveforms as shown in the following table. All time-domain content windows share the same X-axis time scales, which are configured in the :TIMebase subsystem. This includes the Waveform, Time-Ohms, Time-Volts, and Time-% content windows. The Y-axis for time-domain content windows and both axis in frequency domain content windows, are all scaled using commands in the :GRAPh subsystem.

Traces contain the waveform data that is displayed in graphs. In the :TRACe subsystem, the x-axis and y-axis values can only be queried, because they are set by the x-axis and y-axis values of their assigned graph.

Use the :TRACe subsystem to perform the following tasks:

• Create a trace.
• Assign a T-domain or S-parameter to the trace.
• Chang a trace's color.
• Define the trace amplitude levels for measurements.

Use the :GRAPh subsystem to perform the following tasks:

• Scale both axis of frequency-domain graphs.
• Scale the Y-axis only of time-domain graphs.

Commands and Queries for Axis Scaling

Graph Axis	:TIMebase Subsystem	:GRAPh Subsystem	:TRACe Subsystem
NOTES:	Bold Text: Commands that set axis values. Normal Text: Queries that read axis values. Example time values are provided as aid in understanding commands.
Frequency Domain Content Windows (for S-parameters and FFT operator)
X-Axis	—	:X:AUToscale	—
	—	:X:STARt (Hz)	:XLEFt?
	—	:X:SPAN (Hz)	—
	—	—	:XSCale?
	—	:X:STOP (Hz)	:XRIGht?
	—	:X:CENTer (Hz)	:XPOSition? (always at center of axis)
Y-Axis	—	:Y:AUToscale	—
	—	:Y:OFFSet	:YOFFset?
	—	:Y:SCALe	:YSCale?
	—	—	:YTOP?
	—	—	:YBOTtom?
Time Domain Content Windows (for time-domain parameters)
X-Axis	:POSition (100 ps) (with timebase reference set to left)	:X:STARt (100 ps)	:XLEFt? (100 ps)
	:XRANge (2000 ps)	:X:SPAN (2000 ps)	—
	:SCALe (200 ps/div)	—	:XSCale? (200 ps/div)
	—	:X:STOP (2100 ps)	:XRIGht? (2100 ps)
	—	:X:CENTer (1100 ps)	:XPOSition? (1100 ps) (always at center of axis)
Y-Axis	—	:Y:AUToscale	—
	—	:Y:OFFSet	:YOFFset?
	—	:Y:SCALe	:YSCale?
	—	—	:YTOP?
	—	—	:YBOTtom?
Waveform Content Window (Channels, Memories, Functions, …)
X-Axis	:POSition (100 ps) (with timebase reference set to left)	—	—
	:XRANge (2000 ps)	—	—
	:SCALe (200 ps/div)	—	—
Y-Axis	Y-axis values set in :CHANnel, :DIFF, :WMEMory, and etc subsystems.

Unavailable :CWINDow Commands

The following :CWINdow commands are reserved for future use with Waveform content windows. Since only one Waveform content window is available at this time, currently there is no need to use these commands.

• :CHANnel<N>:CWINdow
• :DIFF<N>:CWINdow
• :EMEMory<N>:CWINdow
• :JDMemory<N>:CWINdow
• :WMEMory<N>:CWINdow

Example of Using Content Windows

This example creates four FFT functions and assigns the output of functions 1 and 2 to Group Delay content window 1 and functions 3 and 4 to Group Delay window 2.

  // Configure first FFT function.
:FUNCtion1:FOPerator FFT  // Create an FFT function.
:FUNCtion1:OPERand1 CHAN1A  // Assign input waveform.
:SPRocess1:FFT:DISPlay GDELay  // Select output waveform type.
:FUNCtion1:CWINdow GDELay1  // Assign output waveform to content window.  // Configure second FFT function.
:FUNCtion2:FOPerator FFT
:FUNCtion2:OPERand1 CHAN1B
:SPRocess2:FFT:DISPlay GDELay
:FUNCtion2:CWINdow GDELay1
  // Configure third FFT function.
:FUNCtion3:FOPerator FFT
:FUNCtion3:OPERand1 CHAN2A
:SPRocess3:FFT:DISPlay GDELay
:FUNCtion3:CWINdow GDELay2
  // Configure fourth FFT function.
:FUNCtion4:FOPerator FFT
:FUNCtion4:OPERand1 CHAN2B
:SPRocess4:FFT:DISPlay GDELay
:FUNCtion4:CWINdow GDELay2
// Configure content windows to be zoom tiled.
:DISPlay:WINDow:GDELay1:DMODe ZTILe
:DISPlay:WINDow:GDELay2:DMODe ZTILe
// Select the waveform to be displayed in the zoom-tiled Group Delay content window.
:DISPlay:WINDow:GDELay1:ZSIGnal FUNCtion1  // View function 1 waveform.
:DISPlay:WINDow:GDELay2:ZSIGnal FUNCtion3  // View function 3 waveform.// Autoscale waveforms in each Group Delay content window.
:GRAPh:GDELay1:AUToscale
:GRAPh:GDELay1:AUToscale