User guide

NOTE:Ifareverseactingfeedbackdeviceisbeingused,FB@MINshouldbesettothemaximumprocess
variable value, and FB @ MAX should be set to the minimum process variable value.
77 P GAIN (PROPORTIONALGAIN)
 Thisparametersettingrepresentsthespeedcommandoutput(in%ofmaximumspeed)thatresultsfrom
each1%oferror(1%ofthefeedbackrange;FB@MAXminusFB@MIN).
Example:IfPGAINisprogrammedfor5%,andtheerror(differencebetweensetpointandfeedback)is
10%,thespeedcommandoutputoftheProportionaltermis50%(10x5=50)ofmaximumspeed.
78 I GAIN (INTEGRALGAIN)
 Thisparametersettingrepresentstheramprateofthespeedcommandoutput(in%ofmaximumspeedper
second)thatresultsfromeach1%oferror.
Example: If I GAIN is programmed for 0.5 seconds, and the error is 5%, the rate of rise of the speed
commandoutputoftheIntegraltermis2.5%(0.5x5=2.5)ofmaximumspeedpersecond.
79 D GAIN  (DIFFERENTIALGAIN)
 Thisparametersettingrepresentsthespeedcommandoutput(in%ofmaximumspeed)thatresultsfrom
each 1% per second change in the error.
Example: If D GAIN is programmed for 5 seconds, and the error is increasing at 2% per second, the speed
commandoutputoftheDifferentialtermis10%(5x2=10)ofmaximumspeed.
NOTE: Differential gain is used as a “shock-absorber” to dampen overshoots in fast-acting systems.
However,itcanbeverysensitiveto“noise”onthefeedbacksignalandtodigitizingerrors,soitmustbe
used with caution.
80 PID ACC (PIDACCEL/DECEL)
This parameter sets the acceleration and deceleration rate of the set point reference into the PID unit. When
thesetpointchanges,thisfunctionwill“filter”theinputtothePIDunitbyrampingthesetpointreference
from the previous value to the new value. This will help prevent overshoots that can occur when the PID
control attempts to respond to step changes in set point, resulting in smoother operation. If PID ACC is
set to 0.0 seconds, it is effectively disabled.
81 MIN ALRM (PIDMINIMUMALARM)
 Thisparametersettingrepresentsthevaluethatthefeedbacksignal(inPIDmode)orspeedreferencesignal
(inopen-loopspeedmode)mustfallbelowtoactivatetheMINALARMoutput(seeParameters52,53,
and54).
82 MAX ALRM  (PIDMAXIMUMALARM)
 Thisparametersettingrepresentsthevaluethatthefeedbacksignal(inPIDmode)orspeedreferencesig-
nal(inopen-loopspeedmode)mustexceedtoactivatetheMAXALARMoutput(seeParameters52,53,
and54).
NOTE 1: The MIN/MAX ALARM function can be used to start and stop the drive based on the level of
thespeedreferencesignalorPIDfeedbacksignal.Thisisdonebywiringa2-wirestart/stopcircuitthrough
thedrive’sFormCrelayoropencollectoroutput,andsettingtheFormCrelayoropen-collectoroutputfor
MIN/MAX(seeParameters52,53,and54).WhenthesignaldropsbelowtheMINALARMsetting,the
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