A first-order setpoint-step response model — not a complete programmed-ramp simulation. Drag the setpoint: the controller commands instantly, the sample follows with a first-order lag. The stage’s whole job in one picture.
Schematic first-order response T’ = (Tset − T)/τ with a teaching time constant — the origin of soak times and ramp lag. A step-response teaching model — not a full programmed-ramp simulation, and not data for any real stage.