Persistence mode

Persistence mode superimposes multiple waveforms on the same view, with more frequent data or newer waveforms emphasised with deeper saturation or hotter colours.  This is useful for viewing complex or changing waveforms and can help to make glitches visible even if many subsequent triggers overwrite them.

Switching to Persistence Mode

To switch to persistent mode in the PicoScope software, open the Instruments panel and select Persistence.

To edit the persistence settings, click the time-division lozenge, now labelled Persistence and switch to the Persistence tab.The will show you three different Persistence types, fast, time and frequency, detailed in this article.

Fast persistence

This is the default persistence type, providing a reduced configuration and simplified display options to enable the fastest possible update rate. The PicoScope draws this data on the graph using a colour-coded scale to indicate the densest parts of the waveform in red and the infrequent glitches and waveforms in blue. 

This mode is ideal to quickly detect rare events and glitches hidden in otherwise repetitive waveforms that may not be caught using the standard scope modes. 

Frequency persistence*

Similar to the fast persistence type, frequency mode uses a range of colours to indicate the frequency of waveform data. Red signifying the most frequent data, yellow to blue representing less frequent data. 

Frequency persistence provides more configuration than fast mode, allowing the user to change the Saturation and Decay intensity to adjust the visibility of the least frequent waveform data.

This mode is useful for capturing frequent glitches and spikes in a visual format.

Time persistence*

Time uses colour intensity to indicate the age of the waveform data. The latest data is drawn at full saturation in the selected colour for that channel, with older data being represented by paler shades of the same colour.

This mode allows the user to adjust the Decay time of the oldest waveform data, in seconds. If changed to Infinite, the data will not decay. Alongside this unique setting, time persistence also features configuration to change the Saturation and Decay intensity to adjust the visibility of the oldest waveform data, similar to frequency persistence.

This mode is ideal to catch glitches and spikes that aren’t frequent and may not be visible to the frequency persistence mode. 

*Line drawing mode

In Time and Frequency persistence modes, the line drawing mode can be adjusted between Phosphor, Constant or Scatter. These modes change how a line is drawn between samples that are adjacent in time.

Persistence line drawing toggle switch in PicoScope 7

  • Phosphor: Joins each pair of sample points with a line whose intensity varies inversely with the slew rate. Emulating a traditional phosphor display.
  • Constant: Joins each pair of sample points with a line uniform in colour. 
  • Scatter: Draws sample points as unconnected dots. Providing the user the raw data points.

All demonstrations were made using the Mask demo available on our Mixed Signal Oscilloscope Demo and Training board, available here.