Temperature Controller - Staveb AG

Configuration and Basic Operation 3-13Configuring the OutputParametersControl PeriodThe Control Period parameter is used in the PID control method and allowsyou to adjust the minimum amount of time between ON cycles of theON/OFF output (MV).Figure 3.15Controlperiod(OUT1)• A shorter period may provide better ON/OFF control performance.However, for electromechanical relay outputs we recommend setting thecontrol period to 20 seconds or more. In the case of anelectromechanical relay output, doing this will increase its lifeexpectancy. If necessary, readjust the control period by trial operation tomeet the needs of the application.• Set the control period in the Control Period (OUT1) parameter (InitialSetting function group). Note: The default is 20 seconds.Note: The Control Period parameter allows what is typically called “timeproportioning” ON/OFF control to be done in the 2-PID method.Direct/Reverse OperationFigure 3.16Direct operation refers to control where the manipulated variable (MV) isincreased according to the increase in the process value (PV). Alternatively,reverse operation refers to control where the manipulated variable is decreasedaccording to the increase in the process value (see Figure 3.10). Direct/reverseoperation can be used in ON/OFF or PID control.Publication 900-UM003C-EN-E - January 2004