PLC-FastTrack — Car Factory Simulator

Factory Floor (live PLC outputs)

Sensor low Sensor high Weld active Paint active Engine install active Fault / E-stop

Operator Controls

Sim speed 1.0× QC pass rate 85%

Inputs (PLC %I) — click to force

Outputs (PLC %Q)

Sequencer

Active stepS0_IDLE DescriptionWaiting for Start Step timer0.0 s

Tip: Press ▶ Start to release the SFC from S0_IDLE. With PB_Stop and PB_EStop healthy (green), the latch in S0_IDLE opens and the program advances to S1_LOAD.

Last 10 cycle times —

⚠ Fault injection (instructor mode)

Stuck sensor PE_Weld → 1 Stuck sensor PE_Paint → 1 Stuck sensor PE_Engine → 1 Stuck sensor PE_QC → 1 Belt motor jam Y_Belt ⇏ motion Force every QC to fail 100% Force every QC to pass 100%

Inject a fault and watch the alarm logic, the stuck sensor, or the QC counters react. Great for teaching fault-diagnosis (Bolton Ch. 14).

Equivalent Structured Text (auto-highlighted to match the running step)

How this maps to the SFC

The simulator runs a 100 ms scan loop. Each scan: (1) reads inputs (Start, Stop, E-stop, photoelectric eyes); (2) executes the SFC transitions; (3) writes outputs (conveyor motor, station tools, alarm). The chassis you see on the floor are driven by output bits, never by direct animation — when Y_Belt is high, the chassis advance. When Y_Weld is high, the weld lamp pulses. Toggle E-stop and you'll see the program enter S_FAULT, latch Y_Alarm, and drop every other output — the same fail-safe pattern Bolton describes in Ch. 13–14.