This parameter defines if Wake-up level is used as a static absolute level or as a relativelevel which follows PID setpoint value.Selection 0 = Absolute level (The wake-up level is a static level that does not follow thesetpoint value.)Selection 1 = Relative setpoint (The wake-up level is an offset below the actual setpointvalue. The wake-up level follows the actual setpoint.)PID SetpointSetpointtWake Up LevelFig. 33: Wake-up Mode: absolute levelPID SetpointSetpointtWake Up LevelFig. 34: Wake-up Mode: relative setpointP3.12.2.7 SLEEP FREQUENCY LIMIT 1 (ID1016)See the description of parameter P3.12.2.10.9.10.2 FEEDFORWARDP3.12.4.1 FEEDFORWARD FUNCTION (ID 1059)Accurate process models are usually necessary for the Feedforward function. In someconditions, a gain and offset type of feedforward is sufficient. The feedforward part does notuse the feedback measurements of the actual controlled process value. The feedforwardcontrol uses other measurements that have an effect on the controlled process value.EXAMPLE 1:You can control the water level of a tank with flow control. The target water level is set as asetpoint, and the actual level as feedback. The control signal monitors the flow that comesin.The outflow is like a disturbance that you can measure. With the measurements of thedisturbance, you can try to adjust this disturbance with a feedforward control (gain andoffset) that you add to the PID output. The PID controller reacts much faster to changes inthe outflow than if you only measure the level.PARAMETER DESCRIPTIONS VACON · 15524-HOUR SUPPORT +358 (0)201 212 575 · EMAIL: VACON@VACON.COM 9
