Oscilloscope Cursors

You can measure waveform data using cursors. Cursors are horizontal and vertical markers that indicate X-axis values (usually time) and Y-axis values (usually voltage) on a selected waveform source. The position of the cursors can be moved turning the Entry knob. When you press the Cursors key, it will illuminate and the cursors will turn on. To turn cursors off, press this key again until it is not illuminated, or press the Quick Meas key.

Cursors are not always limited to the visible display. If you set a cursor, then pan and zoom the waveform until the cursor is off screen, its value will not be changed, and if you pan the waveform back again it will have the cursor in the original place.

Cursors can be controlled manually, as described in the next section, or through MATLAB, as described in Commands and Queries below.

To make cursor measurements

Press the front-panel Cursors key.

Press the Source softkey to select the analog channel or math source on which the Y cursors will indicate measurements.

Select the X and Y softkeys to make a measurement.

• X Y Press this softkey to select either X cursors or Y cursors for adjustment.

  The cursor currently assigned to the Entry knob displays brighter than the other cursors.

  X cursors are vertical dashed lines that adjust horizontally and normally indicate time relative to the trigger point. When used with the FFT math function as a source, the X cursors indicate frequency.

  Y cursors are horizontal dashed lines that adjust vertically and normally indicate Volts or Amps, dependent on the channel Probe Units setting. When math functions are used as a source, the measurement units correspond to that math function.

• X1 and X2 The X1 cursor (short-dashed vertical line) and X2 cursor (long-dashed-vertical line) adjust horizontally and indicate time relative to the trigger point for all sources except math FFT (frequency is indicated). In XY horizontal mode, the X cursors display channel 1 values (Volts or Amps). The cursor values for the selected waveform source are displayed within the X1 and X2 softkeys.

  Turn the Entry knob to adjust the X1 or X2 cursor when its softkey is selected.

• Y1 and Y2 The Y1 cursor (short-dashed horizontal line) and Y2 cursor (long-dashed horizontal line) adjust vertically and indicate values relative to the waveform's ground point, except math FFT where the values are relative to 0 dB. In XY horizontal mode, the Y cursors display channel 2 values (Volts or Amps). The cursor values for the selected waveform source are displayed within the Y1 and Y2 softkeys.

  Turn the Entry knob to adjust the Y1 or Y2 cursor when its softkey is selected.

• X1 X2 Press this softkey to adjust the X1 and X2 cursors together by turning the Entry knob. The ΔX value will remain the same since the cursors adjust together.

  You can adjust the X cursors together to check for pulse width variations in a pulse train.

• Y1 Y2 Press this softkey to adjust the Y1 and Y2 cursors together by turning the Entry knob. The ΔY value will remain the same since the cursors adjust together.

Commands and Queries

Maintained by John Loomis, last updated 20 February 2009