Using the Measurement Display

IVI Soft Front Panels

Using the Measurement Display

IVI Soft Front Panels—Scope has sophisticated waveform measurement capability in the measurement display of the front panel. Complete the following steps to control the measurements that appear in the measurement display:

  1. Select Measure»Channel»Measurement.
  2. Enable the channel by selecting it in the channel selector.
Note  To ensure accurate waveform measurements, use the following guidelines:
  • The waveform must lie completely within the top and bottom confines of the display. Adjust the Volts/Division and/or Vertical Offset controls appropriately.
  • If you are measuring frequency or period, at least four complete periods of the waveform must appear in the graphics display. Adjust the Timebase control appropriately.
  • Remember that IVI Soft Front Panels—Scope detects when a measurement is being clipped or when there is not enough data being acquired to make valid frequency or period measurements. In these cases, +Over, -Over, or ?  appears in the display in place of the usual numeric information.

Measurements

Mean Average value of the signal.
RMS Root Mean Square (RMS) or AC component of the signal.
Max Maximum sampled voltage value.
Min Minimum sampled voltage value.
Pk-Pk Maximum voltage swing (Max – Min).
High The value that best represents the active or high position of the signal.
Low The value that best represents the inactive or low position in the signal.
Amplitude Signal amplitude (High – Low).
Overshoot The amount by which the maximum value exceeds the High value (Max – High).
Undershoot The amount by which the minimum value is lower than the Low value (Low – Min).
Frequency The frequency of the signal in Hz. To give an accurate frequency measurement, the display must show at least four complete cycles.
Period The period of the signal in seconds. To give an accurate period measurement, the display must show at least four complete cycles.
Rise Time The time required to rise from 10 percent amplitude to 90 percent amplitude.
Fall Time The time required to fall from 90 percent amplitude to 10 percent amplitude.
Positive Width The average period of time between the rising edge and the next falling edge, measured at 50 percent signal amplitude.
Negative Width The average period of time between the falling edge and the next rising edge, measured at 50 percent signal amplitude.
Positive Duty Cycle The percentage of time that the signal is in a high signal state. (Positive Width × 100 %) / Period.
Negative Duty Cycle The percentage of time that the signal is in a low signal state. (Negative Width × 100 %) / Period.
Slew Rate The rate at which the signal changes in volts/seconds between the 90 percent and 10 percent levels. (90% amplitude – 10% amplitude)/Rise Time.

Related Topic

Using Cursors to Make Waveform Measurements