I just want to know more about floating point control.
1) Why does it called floating point control?
2) Please confirm my understanding of floating point control is correct.
Floating point control is also called 3-position control (clockwise, counter-clockwise, off). Basically, there are two DO's or BO's signals (24VAC signal) to control a device (i.e. valve actuator). One DO drives the actuator in one direction (i.e. clockwise) and the other DO drives the actuator in another direction (i.e. counter-clockwise). If there is no input to the actuator, the actuator stays in that current position (non spring return; fail in place). And floating point control depends on time. For example, for a 90-second-run-time valve actuator, the DDC controller needs to send a DO signal for 90 seconds in order to completely open or close the valve. If the DDC controller send a DO signal to the valve actuator for 45 seconds when the valve is completely close, the valve will open 50%. The valve actuator will do self-calibration regularly (how often?).
3) What is floating point control is cheaper than modulating control? Is it the circuit board design or the manufacturer process of the parts (i.e. valve actuator)?