Lena shook her head. "No. We need an SFC." She opened CODESYS and created a new POU (Program Organization Unit). She chose Sequential Function Chart (SFC) . No ladder. No structured text loops. Just pure, visual, time-tested sequence logic.
Then she wrote a parallel :
Lena pointed at the HMI. "No. The SFC saved it. Look—step history." codesys sfc example
She added a parallel to the main sequence:
At 3:47 PM, a bearing seized on the acid bath agitator. The temperature spiked to 110°C. Acid_Temp > 95C triggered a pre-programmed fault. Lena shook her head
Crane_Up := TRUE; Acid_Drain_Valve := TRUE; // SD qualifier keeps this ON Emergency_Alerter := TRUE; Inside Step 0 's Entry Action:
Lena needed an .
The SFC was in with a coil halfway submerged.