IEC 61131-3 PLC & SCADA Modbus Automation — 250 kVA Generator ATS & 4-20mA PID Control

Industrial PLC & SCADA Automation (IEC 61131-3 Structured Text / PLCopen XML): Automatic Transfer Switch (ATS / QTA) control for a 250 kVA diesel generator with ANSI 27/59 voltage/frequency supervision and contactor interlocking, closed-loop 4–20 mA pressure PID control with NAMUR NE43 fault detection, complete Modbus TCP/RTU register map, and multi-wire 24 VDC I/O & control schematics in QElectroTech. Repository: https://github.com/r-menegueli/automacao-clp-scada-iec61131