PLC Simulator
Feature: Wiring & Fault-Finding Tutor

Wire industrial panels and diagnose faults — in your browser.

An interactive lab with 29 wiring lessons and 19 fault-finding scenarios. You drag wires through realistic panel layouts, route DIN-rail circuits, and use a virtual multimeter to trace physical faults. Five foundation labs are Free; advanced wiring and all fault diagnosis are Pro.

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What you'll build

Three representative lessons across the curriculum. The full track has 29 wiring lessons (power, sensors, motor control, safety, instrumentation and communications) and 19 fault scenarios.

Wiring 1

24 VDC Power Supply & Grounding

Wire AC mains into a DIN-rail PSU, route 24 V to the PLC base, and bond every PE to the ground bar. The free starting lesson.

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Fault 1

Photoeye polarity diagnosis

A photoeye is wired NPN where the PLC card expects PNP. Use the multimeter to find which terminal is reading wrong.

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Wiring 8

Safety circuit with E-stop and contactor

Wire a Category-3 safety circuit: E-stop button → safety relay → contactor. Mistakes here matter.

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How the lab works

  • Drag-route wiring. Click a terminal, drag to another, drop to connect. Wires snap to grid, animate as they're laid down, and update the live circuit graph.
  • Per-connection grading. Submit and the grader checks every connection against the lesson's expected map. Wrong wires highlight red; correct wires green.
  • Virtual multimeter. In fault scenarios, the multimeter reads the real voltage at any terminal. Use it to trace the circuit and isolate the fault.
  • Tier-aware access. Five foundation labs are Free. Advanced wiring and all fault-diagnosis labs show a useful preview, then require Pro for the interactive circuit.
Wiring Lab — Lesson 8 (Safety Circuit)Fault detected
PSU 24V+ / 0V / PE
K1 ContactorNO/NC swap
⚙Motor M13-phase
Multimeter
0.0 VDC
Expected 24 V — open contact
Score
7 / 8 connections

Who it's for

Maintenance technicians

Sharpen fault-tracing skills you'll use on the floor without taking equipment offline.

Panel builders

Practice DIN-rail layouts, control wiring, and safety-circuit topology before you cut a single wire.

Students & career changers

Build hands-on intuition for industrial wiring without the cost or safety risk of real hardware.

FAQ

Do I need any installs?
No. Everything runs in your browser. Phaser-based canvas — no plugins, no native binaries.
What's free vs paid?
The foundation labs are free to start. The advanced motor-control, instrumentation, safety, communications and fault-diagnosis labs require a Pro account.
How long does each lesson take?
10–25 minutes for wiring lessons depending on complexity. Fault scenarios are typically 5–10 minutes once you know the diagnostic technique.
Do I need real hardware?
No. The lab is self-contained. That said, time on real panels is irreplaceable — this is a complement to hands-on practice, not a substitute.
How is this different from the fault-diagnosis section on the homepage?
The homepage <FaultSection> covers logic-layer faults — bugs in your PLC code found via scan-cycle highlight and cross-reference. This wiring tutor covers physical-layer faults — broken wires, polarity reversals, contact swaps inside a real panel, found by tracing the circuit with a multimeter.

Ready to wire your first panel?

Start with Lesson 1 — free on signup, no install.

Try Lesson 1 free →