A structured path through the skills every PLC programmer needs — written for people who learn by doing, not by reading PDFs. Every lesson is paired with a live simulator exercise.
First 4 lessons free. No credit card required.
Each lesson takes 20–35 minutes and ends with a graded exercise in the live simulator.
What a PLC is, what it does, and how it fits into an automation system. Scan cycle, I/O modules, CPU, memory map.
Contacts, coils, and rungs. How ladder logic maps from a relay circuit. Writing your first motor start/stop program.
TON, TOF, CTU, CTD. Preset vs accumulator. Using timers to delay motor start and counters to count parts.
How a seal-in (self-latching) rung works. Why order matters. The classic start/stop motor control circuit with latch.
SET/RESET coils vs seal-in rungs. When each is the right choice. Latch coil hazards and how to avoid them.
Proximity, photoelectric, and inductive sensors. PNP vs NPN wiring. How sensor type maps to contact type in ladder logic.
Star-delta starter, overload relay, forward/reverse interlocking. Full motor control program from contactors to PLC.
Step-based control using integer comparison. Building a 4-step conveyor sequence that pauses and restarts reliably.
Scaling raw counts to engineering units. 4–20 mA loop wiring. Reading a pressure sensor and triggering an alarm.
Proportional, integral, and derivative explained. Tuning a PID loop for a temperature controller in the simulator.
Systematic fault-finding using scan-cycle highlight, variable table, and cross-reference. Three injected-fault exercises.
IEC 61131-3 ST syntax. IF/THEN/ELSE, FOR loops, function blocks. Rewriting a ladder program as Structured Text.
Plain-language concept explanations written for technicians and engineers — not textbook academics.
Write real ladder logic against a running machine simulation. Automated test cases tell you when you pass.
Slow down the scan and watch each rung execute step by step. See why your logic works — or why it doesn't.
First 4 lessons free. No credit card required.
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