Forty-one levels, worked in order, each one ending in an automated commissioning test. It runs in a browser on a college PC or a student's phone. No installation, no licences, no accounts, and nothing collected about anybody.
We are Prizm Technical, a controls engineering consultancy — not a training company. We built this because we keep meeting capable electricians, fitters and maintenance engineers who could do this job and never found a way in. A trainer rig has one seat. This has thirty.
The first chapter does not begin with software. It begins with the direct-on-line starter your students have already wired — start button, stop button, contactor, holding contact — and shows that ladder logic is that circuit, drawn the way it has always been drawn:
For a student who has held a contactor, that is a moment of recognition rather than a new subject. It is the fastest confidence win we know of.
| Chapter | Levels | Outcomes |
|---|---|---|
| Relay panel to rung | 8 | Contacts and coils, series/parallel as AND/OR, NO vs NC, latching, the seal-in, fail-safe wiring, hand/off/auto |
| Time and count | 6 | TON and TOF, oscillators, rising edges and one-shots, counters, star-delta with interlocking |
| Real machines | 4 | Step sequencers, reversing drives, hysteresis, two-hand anti tie-down control |
| FBD | 3 | Logic blocks, SR vs RS and reset dominance, where an interlock belongs |
| SCL / Structured Text | 4 | Assignment, IF/ELSIF, function-block calls, CASE state machines |
| STL / Statement List | 3 | The RLO, first check, AND-before-OR, nesting, S7 timers |
| The Gauntlet | 10 | Applied jobs: first-out annunciation, batch sequencing, part tracking, duty/standby, ramp and soak, fault handling, cascade start |
| Certification | 3 | Fault-finding someone else's code, a ten-clause spec, and a twelve-clause machine with no hints |
Safety is woven through rather than bolted on: why stop circuits are wired normally closed, why a guard must break the latch and not gate the output, contactor interlocking, anti tie-down, and why an E-stop also goes through a hardwired safety relay.
Every level ends in an automated commissioning test. It either passes or it tells the student exactly which assertion failed, in plain English.
No timers, no lives, no leaderboards. Unlimited retries, hints always available. The barrier for adult learners is confidence, not ability.
Every briefing has an Apprentice version and a Workshop version, switchable. Same content, different register.
Finishing produces a printable certificate with a completion record — levels, stars, hints used and a reference code.
Power flow is shown by colour, line weight and motion together, with high-contrast and colour-blind palettes. Full keyboard and screen-reader support.
Once loaded it keeps working with no connection — useful on a poor college network or a phone in a workshop.
No accounts. No cookies. No analytics. No tracking. Nothing leaves the device.
Static files over HTTPS with no third-party requests of any kind. Progress is stored in the student's own browser and is never transmitted. The only contact route in the whole site is an optional careers form on the final certificate, restricted to over-18s. Full detail on the privacy and data page.
%I0.0, SCL, STL). Chapters 1–3 are platform-neutral.There is a six-session scheme of work (printable) with session plans, discussion prompts and assessment suggestions. Take it, cut it, ignore it — the levels are the fixed thing.
We have deliberately not claimed alignment to any specific qualification, because we are engineers rather than awarding-body specialists. The outcomes are written so you can map them to your own unit codes.
If you teach this and want to use it with a group, or you want to talk about work experience, site visits or apprenticeships for your students, we would genuinely like to hear from you. We are a working consultancy and we would rather more people could do this job.