Temperature Controller - Staveb AG

Parameter Adjustments and Application Considerations 4-13OutputFigure 4.25 Dead BandDead band:dead band width = positiveOutputOverlap band:dead band width = negativeHeating sideCooling sideHeating sideCooling sidePVPVSet pointSet pointCooling Coefficient (Heating and Cooling Control)When the heating and cooling control mode and PID control method areselected, the Cooling Coefficient parameter can be used. If the heating andcooling functional characteristics of the control target greatly differ, this couldlimit satisfactory control performance from being obtained by the same PIDvalues. To reduce the possibility of this occurring, adjust the proportional band(P) at the cooling side of the set point using the cooling coefficient to balancecontrol between the heating and cooling sides. In heating and cooling controlthe proportional band, (P) at the heating or cooling side is calculated by thefollowing formula:Control output 1 (heating side): P = PControl output 2 (cooling side): P = P x cooling coefficientThe control output 2 (cooling side) coefficient is applied to control output 1(heating side) proportional band (P) to obtain control whose characteristicsdiffer from those on the control output 1 side.Figure 4.26 Cooling CoefficientOutputOutputControl output 1 sideP x 1.0Control output 1 sideP x 1.00Control output1 side PControl output 2 side PSet pointControl output 1 side P x 0.8PVControl output1 side P0Control output 2 side PSet pointControl output 1 side P x 1.5PVSetup of Heating and CoolingTo configure the heating and cooling control mode, set the Standard/Heatingand Cooling, Dead Band, and Cooling Coefficient (when using the PIDmethod) parameters.Publication 900-UM003C-EN-E - January 2004