Probes are schematic objects that are used to help extract data from the simulation results.

The primary functions of probes are:

  • Providing a clear and convenient way of acquiring and viewing common measurements, such as voltages, branch current, and power.
  • Automating the output variable selection process in analyses (such as Transient and AC Sweep). After an analysis is run, variables from probes are automatically plotted in the Grapher.
  • Annotating important points.

The available probes are:

  • Voltage, Current, Voltage and Current—These probes can measure voltage, current or both. Use the probe's properties dialog to change as needed. The symbol updates to reflect the selection. You can optionally set the reference probe.
  • Power—Measures the power dissipated or generated by a component.
  • Differential voltage—Click once to place a voltage probe and again to place a reference probe. The voltage measured between these two points is the differential voltage.
  • Reference—Provides a reference net to a voltage probe. Without a reference probe, a voltage probe will reference net 0. Use for differential voltage measurements. This an alternative to placing a pair of Differential voltage probes. Use if you have placed a number of voltage probes that you want to reference to a given point.
  • Digital—Measures the digital state value. In interactive simulation, the symbol updates dynamically with 1, 0, X to denote the High, Low, and Unknown state respectively.

Place the voltage, current, digital, and voltage reference probes on wires. For example:

Place the power probe on top of a component. For example:

If a probe is not placed correctly, it is considered disconnected and is shown greyed-out. For example:

Probes take no measurements in this state.

  Probes stay with wires and components when the wires are moved. They are not deleted when their nets, net segments, or components are deleted.