Logix5000 Controllers General Instructions - SLAC Confluence

Special Instructions (FBC, DDT, DTR, PID) 507Specify configurationSelect the Configuration tab. You must click OK or Apply for anychanges to take effect.In this fieldPID equationControl actionDerivative ofLoop update timeCV high limitCV low limitDeadband valueNo derivative smoothingNo bias calculationNo zero crossing indeadbandPV trackingCascade loopCascade typeSpecifySelect independent gains or dependent gains (.PE).Use independent when you want the three gains (P, I, and D) to operate independently.Use dependent when you want an overall controller gain that affects all three terms(P, I, and D).Select either E=PV-SP or E=SP-PV for the control action (.CA).Select PV or error (.DOE).Use the derivative of PV to eliminate output spikes resulting from setpoint changes. Usethe derivative of error for fast responses to setpoint changes when the algorithm cantolerate overshoots.Enter the update time (.UPD) for the instruction.Enter a high limit for the control variable (.MAXO).Enter a low limit for the control variable (.MINO).Enter a deadband value (.DB).Enable or disable this selection (.NDF).Enable or disable this selection (.NOBC).Enable or disable this selection (.NOZC).Enable or disable this selection (.PVT).Enable or disable this selection (.CL).If cascade loop is enabled, select either slave or master (.CT).Specifying AlarmsSelect the Alarms tab. You must click OK or Apply for any changes totake effect.In This FieldPV highPV lowPV deadbandpositive deviationnegative deviationdeviation deadbandSpecifyEnter a PV high alarm value (.PVH).Enter a PV low alarm value (.PVL).Enter a PV alarm deadband value (.PVDB).Enter a positive deviation value (.DVP).Enter a negative deviation value (.DVN).Enter a deviation alarm deadband value (.DVDB).Publication 1756-RM003I-EN-P - January 2007