122.What is Bump-less transfer and how to achieve it?

Controllers can be on Cascade/Auto/Manual Modes. Whenever the controller status is changed, the process should not experience a variation(BUMP). In order to achieve this, the output should be held in its last value before the change in status and the output has then to be varied as per the conrol requirements. Different "Tracking" computations can be configured to achieve the same(PV-SV track etc.), so that the controller does not see a deviation during Mode change.