Simulation

Start with the play button or F5. The simulator solves the whole sheet continuously: it finds the potential of every wire, decides which coils are energised, which contacts are closed and which loads run, and repeats until the circuit settles — so self-holding, interlocks and timers behave as in a real panel.

Operating devices

Click a push button to press it, a switch to toggle it, a breaker to open or close it, a fuse to blow or replace it, a sensor to actuate it.
Potentiometers and transmitters open a large slider — made for whiteboards.
PLC: click an output to force it; click the mode area to switch RUN/STOP.
Generator: click to start; it delivers voltage after its start-up time.
Supply: click to simulate a power outage of that phase (the line turns grey with ✕).

Clock and speed

The floating bar shows the simulation time. Pause freezes everything; the speed buttons run timers at ×1, ×10 or ×60 so a 5-minute timer does not need 5 minutes of lesson time.

Faults and protection

Short circuit between different potentials (L1–N, L1–L2, L+–M): the protection with the smallest rating that clears the fault trips — selectivity as in a real installation. The fault is reported with the two potentials involved.
Earth fault (a live conductor connected to PE): the RCD trips first; MCBs stay closed.
Overload: the simulator sums the currents of the loads fed through each protection. Thermal relays, MCBs and fuses heat up along their tripping curve and trip when the thermal image reaches 100 %. Thermal relays reset by click; MCBs show a trip indication.
Wrong voltage: coils and loads need the right kind of voltage (AC or DC) and at least 85 % of their rated value (IEC 60947-4-1). Mixing AC and DC, or feeding a 24 V coil with 230 V, is reported.
Three-phase motors show rotation direction from the phase sequence, star or delta connection, missing phase and overvoltage. With an inverter they show frequency and speed.

Messages

During simulation a message area lists faults, warnings (undervoltage, missing phase, out-of-range analog input…) and PLC states. The design check (toolbar) works without simulation: it reports a missing supply, unconnected terminals, duplicate designations and PLC addresses used in Ladder but not wired.