Simulation Engines and Models

WireFrame includes a simulator for everyday use. You can also connect another supported simulator when a project or model requires it.

Choose a simulator

Open Simulation → SPICE Simulation Panel, then go to Setup → Engine.

Simulator	When to choose it
ngspice	Recommended for most projects; included with WireFrame
ngspice (CLI)	Use an ngspice installation already available on your computer
Xyce	Use when your project has been prepared and validated for Xyce
LTspice	Use when you need to compare with an LTspice-compatible model or workflow

Unavailable simulators remain visible and show why they cannot be used.

Connect an external simulator

1. Install the simulator using its official installer or package.
2. Open Preferences → Simulation.
3. Find the simulator under Engines.
4. Click Browse… and select its executable file.
5. Confirm that its status changes to found.
6. Return to the Simulation Workbench and select it under Setup → Engine.

Use Clear to remove a custom location and let WireFrame search the normal system locations again.

Set your simulation defaults

Under Preferences → Simulation, you can choose:

• the default analysis;
• the default transient duration;
• the default time step;
• executable locations for optional simulators.

These choices are restored the next time WireFrame starts.

Resolve a missing model

Some components—especially integrated circuits and transistors—need a simulation model from the manufacturer.

1. Open the workbench Models tab.
2. Find the item marked Missing.
3. Note the component designator and requested model name.
4. Download the correct SPICE model from the component manufacturer.
5. Import the model and assign it to the component.
6. Run Preflight again.

Match the exact component

A model for a similar part can produce convincing but incorrect results. Confirm the manufacturer part number, model name, pin order, and package against the datasheet.

Before running

Choose the circuit scope, run preflight, resolve every missing or incompatible model, select the intended simulator, and then run. Repeat preflight whenever you change a model or engine.

Image — Engine and model readiness

Image needed

Capture Setup → Engine beside Models → SPICE model library in a two-panel composite. Show one selected engine and model readiness without revealing personal executable paths. Suggested size: 1400 × 760 px.

Troubleshooting

What you see	What to check
Not installed	Select the correct executable in Preferences → Simulation
Run is disabled	Run Preflight and read the readiness message
A model is missing	Confirm the component's assigned model and datasheet
No waveform appears	Select a signal, check the analysis, then review the simulation log
Two simulators disagree	Confirm both runs use the same sources, loads, model version, and settings