🚦 The Suspiciously Fun PLC Series · Track 08The PLCopen state machine:
The PLCopen state machine:
why your axis says no.
Every PLCopen axis is always in exactly one state, and a motion command only works from the states that allow it. Send MC_MoveAbsolute to a disabled axis and nothing moves, because the state machine rejected it. This track maps the single-axis states onto driving a car, lets you drive the live diagram yourself, shows how every fault ends in ErrorStop and how MC_Reset gets you out, and finishes with axis groups that follow the same pattern.
The idea
🚦 why an axis refuses commands out of order · 🗺️ the states in plain English, mapped onto a car.
Drive it, then level up
🎮 fire commands at the live diagram and watch illegal ones bounce · 🚨 faults and MC_Reset · 🤝 coordinated axis groups.
🌐
The diagrams here show the single-axis states this lesson drives: Disabled, Standstill, Homing, Discrete Motion, Stopping and ErrorStop. The full PLCopen diagram also has Continuous Motion and Synchronized Motion, which follow the same rules. TwinCAT 3 implements these function blocks in Tc2_MC2.
Best after Track 07 (motion & the real world), so MC_Power and MC_MoveAbsolute already look familiar.