industrialsafetysequencing
Control system sequencing
Interlock and phase logic expressed as requirements — semantics, not just ladder rungs.
startup_sequence {
valve must close before heater enables
pressure must reach setpoint before valve opens
aligns with [safety_interlock]
@tags: (iec-61131, critical)
@status: verified
}idle ──► preheat ──► pressurize ──► run
│ │
└── [safety_interlock] ◄───┘