Setpoint
also: SP · target value · reference
The target value a control system tries to hold, such as a temperature, speed or pressure; the controller acts on the gap between setpoint and measurement.
The setpoint is what the user, or a higher-level system, asks for. The controller compares it with the process variable (the measurement) and acts on the error. In a thermostat the setpoint is the temperature on the dial; in a motion system it can be a position that changes every millisecond.
Setpoints are a product decision, not only a control one. How fast should they be allowed to change? Should large changes be ramped to avoid shocking the mechanism or the occupants? What range and units are shown to the user, and who is allowed to change them? Abrupt setpoint steps are a common cause of overshoot and integral windup; ramping or filtering the setpoint is a cheap fix.
Founder takeaway
Define setpoint ranges, ramp rates and permissions as part of the product requirements, not as an afterthought in firmware.
engineer review pending