HP 1660CS-Series User Manual page 214

The channel selected for assignment to the Va marker does not have to be
displayed in the waveform area. If the selected waveform is not in the
waveform area of the screen, the Va marker will not be displayed. If there
are multiple occurrences of the selected waveform in the waveform area of
the screen, only the uppermost occurrence of the waveform will display the
Va marker.
Overlay and waveform math traces cannot be selected for voltage marker
placement.
The Vb On field works similarly.
Va Volts field
The Va marker is shown on the waveform display as a horizontal dashed line.
The voltage displayed in the Va Volts field is measured relative to the
zero-volt reference for this channel.
When you select the Va Volts field, you can change the voltage value by
turning the knob or by entering a voltage value from the pop-up keypad. The
range of voltage levels for the Va Volts field is ±2 times maximum range for
the selected channel. The maximum range value is affected by the probe
factor and v/div settings.
The Vb Volts field works similarly.
Va to Vb field
This field displays the difference between the Va and Vb markers. This value
is dependent on channel selections and represents Vb minus Va.
Center Screen Field
The Center Screen field appears on the right side of the Marker menu. The
Center Screen field centers the screen on the chosen timebase marker.
If time markers are turned off, the only marker choice available on the Center
screen pop-up will be the trigger marker. If time markers are turned on, the
Tx and To markers will also appear in the Center Screen pop-up menu. If the
auto time markers are enabled, only the trigger marker appears in the Center
Screen pop-up menu.
Selecting one of the possible time markers for centering the waveform data
will cause the timebase delay value to be changed such that the selected
marker is positioned at the center of the screen. All acquisition channels are
shifted when the trace data is centered. The timebase delay field value will
be updated when the centering operation is performed.
The Scope Marker Menu
Voltage Markers options
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