Handbook - Eurotherm Ltda

T820 HANDBOOK5.2 LOOP_PID FUNCTION BLOCKThe instrument control loop is configured using the Loop function block and up to 7 (seven) additional Tune_Setblocks, allowing a total of eight sets of tuning parameters for an individual control loop.NoteEach set of PID tuning parameters, one additional set of tuning parameters per Tune_Set block,provides specific tuning for different levels of temperature, particularly useful in control systems wherethe response to the cooling power is significantly different to that of the heating power.The LOOP_PID block consists of the following pages• MainTo setup the operating parameters of the Control Loop. These are an overview of the main parameters such asAuto/Manual select, current PV, current output demand, selected SP value and working SP value.• SetupTo configure control type for each channel of the selected loop• TuneTo set up and run the Auto Tune function• PIDTo set up 3 term, Proportional Band, Integral Time, and Derivative Time (PID) control parameters• SPTo select and adjust different setpoints, setpoint limits, rate of change of setpoint• OPTo set up output parameters such as limits, sensor break conditions• DiagTo diagnose Control Loop problems, such as sensor break detection, loop break detection• AlarmsTo setup alarm parameters used to indicate operational extents have been exceededNoteParameters are wired using the LINtools Engineering Studio, as part of a strategy, see LIN BlockReference Manual, Part no. HA 082 375 U003, for full block parameter details.Chapter 5Page 5 - 2HA029131Issue 3 Feb 08