Static Simulation Probes

To help verify your circuit designs, Altium Designer 16 now includes static simulation probes. Placing probes allows you to interactively test voltage, power, and current, providing valuable feedback for your design and helping to predict the behavior of your circuit.

Access

Static simulation probes can be accessed in the following ways:

• From the main toolbar, click Simulate » Place Probe. Select the probe of your choice. 
• From the Mixed Sim toolbar. To open the toolbar, right-click in the toolbar next to Help select Mixed Sim to add the Mixed Sim toolbar to your workspace. The toolbar can float separately or you can drag and drop it into your actual toolbar.

Selecting a Probe

The Mixed Sim toolbar contains a number of probe placement buttons, including the Voltage Probe, the Voltage Difference Probe, the Current Probe, and the Power Probe.

• Voltage Probe - view voltage at a point in the circuit. This probe can be placed on a wire or pin.
• Voltage Differences Probe - view where voltage changes within a circuit (for example, across a resistor). Selecting Voltage Differences Probe will allow you to place two probes: a positive (+) and negative probe (-). These probes can be placed on a wire or pin.
• Current Probe - test for current at a point in the circuit. This probe can only be placed on a pin.
• Power Probe - test the power level at a point in the circuit. This probe can only be placed on a pin.

After selecting a probe, you can place it on the desired wire or pin in the schematic. You can place multiple probes at once, or, after placing one probe, right-click to exit probe placing mode. Alternatively, you can place multiple probes of different types (for example, two Voltage Differences probes and a Power probe).

Reviewing Probe Data

When using simulations, you can use the Analyses Setup dialog to define the analyses types you want to include in your design simulation, the scope of the simulation and the signals to be automatically displayed upon completion of the simulation. To open the Analyses Setup dialog, click on the Mixed Sim toolbar. Within the dialog, setting the SimView Setup to Show active probes will ensure that the charts in your SDF file accurately reflect the active probes.

Selecting Show active probes from the SimView Setup drowndown menu.

Alternatively, selecting Show active signals/probes from the SimView Setup will plot both the waveforms selected in the active signals and the active probes. Click Show Active Probes/Signals to toggle back and forth between viewing signals or probes.

Click to run the Mixed Signal Simulation. Running the simulation will open an SDF file which displays simulation feedback in a chart. If you have placed multiple probes, then these waveforms will each be displayed in a separate plot. It may be easiest to split your workspace in order to view your Schematic Editor and the SDF file at the same time.

Horizontal split screen view of both the schematic and the related SDF file.
The SDF charts show feedback for the Voltage Probe placed on the ProbeTest net (top/blue), and for the Power Probe placed next to the RF resistor (bottom/green).

You can actively move the static probes around the schematic to see how feedback changes across your circuit. Whenever you place or move probes, you will need to re-run the Mixed Signal Simulation to update the charts on your SDF file. When you rerun a simulation, the newly probed points will be added in separate plots and the waveforms for any removed probes will also be removed. Otherwise, waverforms will remain as you had previously arranged them.

To make viewing the charts easier, you can bold the waveforms. To easily bold a waveform, simply click on the waveform name in the legend to the right (for example, ProbeTest, as seen above in blue). You can also set waveforms to bold by default (right-click anywhere in the SDF document and select Document Options from the context menu).

Restrictions

• Not all circuits can be simulated. The simulator requires a simulation model for each component. You can use the Libraries panel to check if your components have simulation models.
• Voltage Difference probes must be placed as pairs.