Codesys Sfc Example -

[Step 20: DIP] --(45s & no EStop)--> [Step 30: RINSE] | | (EStop_Pressed) v [Step 99: EMERGENCY_RETRACT] --(Acid_Level<5%)--> [Step 0: IDLE] Inside Step 99 's Action:

Then she wrote a parallel :

Lena pointed at the HMI. "No. The SFC saved it. Look—step history." codesys sfc example

She closed her laptop. "Time to add a heartbeat monitor to the agitator motor," she said. "And maybe buy Dave a coffee." | Concept | In the Story | | :--- | :--- | | Step | Step 20: DIP | | Transition | Condition between steps (e.g., T#45s ) | | Action Qualifier | N (Normal), S (Set), SD (Set Dominant) | | Jump | Jump to Step 99 from a transition | | Parallel Branch | E-Stop logic running alongside main sequence | | Step Entry/Exit Actions | Code that runs when step activates/deactivates | | Implicit Action | Acid_Emergency attached to Step 20 | [Step 20: DIP] --(45s & no EStop)--&gt; [Step

The transition to Step 0 required Acid_Level < 5% . But the drain valve closed after 2 seconds because the "DIP" step's action had been deactivated. She forgot: Actions in SFC only run while their step is active. Look—step history

Acid_Drain_Valve := FALSE; // Reset only when safe Emergency_Alerter := FALSE; Three weeks later, the line went live.