In floating control, the specific output of the controller is not uniquely determined by error. If the error is zero, the output does not change but remains (floats) at whatever setting it was when error went to zero. When error moves of zero, the controller output again begins to change.
Similar to two-position mode, there will be a neutral zone around zero error where no change in controller output occurs.
Popularly there are two types:
(a) Single Speed
(b) Multiple Speed
Single Speed: In this mode, the output of the control element changes at a fixed rate when the error exceeds the neutral zone.
Multiple Speed: In this mode several possible speeds (rate) are changed by controller output. Usually, the rate increases as the deviation exceeds certain limits.