FC 300 Design GuideHow to Program" Parameters: Controllers" 7-** ControllersParameter group for configuring application controls." 7-0* Speed PID Ctrl.Parameters for configuring the speed PID control.7-00 Speed PID Feedback SourceOption:*Motor feedb. P1-02 (FC 302 only) [0]24V encoder [1]MCB 102 [2]MCO 305 [3]Function:Select the encoder for closed loop feedback.The feedback may come from a different encoder(typically mounted on the application itself)than the motor mounted encoder feedbackselected in par. 1-02.This parameter cannot be adjusted whilethe motor is running.NOTEIf separate encoders are used (FC 302only) to ramp settings parameters inthe following groups: 3-4*, 3-5*, 3-6*,3-7* and 3-8* must be adjusted according to thegear ratio between the two encoders.7-02 Speed PID ProportionalGainRange:0.000 - 1.000 * 0.015Function:Enter the speed controller proportional gain.The proportional gain amplifies the error (i.e.,the deviation between the feedback signal andthe set-point). This parameter is used with par.1-00 Speed open-loop [0] and Speed closed-loop[1] control. Quick control is obtained at highamplification. However if the amplification is toogreat, the process may become unstable.7-03 Speed PID Integral TimeRange:2.0 - 20000.0 ms *8.0 msFunction:Enter the speed controller integral time, whichdetermines the time the internal PID control takesto correct errors. The greater the error, the morequickly the gain increases. The integral time causesa delay of the signal and therefore a damping effect,and can be used to eliminate steady state speederror. Obtain quick control through a short integraltime, though if the integral time is too short, theprocess becomes unstable. An excessively longintegral time disables the integral action, leadingto major deviations from the required reference,since the process regulator takes too long toregulate errors. This parameter is used with Speedopen-loop [0] and Speed closed-loop [1] control,set in par. 1-00 Configuration Mode.7-04 Speed PID Differentiation TimeRange:0.0 - 200.0 ms *30.0 msFunction:Enter the speed controller differentiation time. Thedifferentiator does not react to constant error. Itprovides gain proportional to the rate of change ofthe speed feedback. The quicker the error changes,the stronger the gain from the differentiator. Thegain is proportional with the speed at which errorschange. Setting this parameter to zero disablesthe differentiator. This parameter is used withpar. 1-00 Speed closed-loop [1] control.7-05 Speed PID Diff Gain LimitRange:1.000 - 20.000 *5.000Function:Set a limit for the gain provided by the differentiator.Since the differential gain increases at higherfrequencies, limiting the gain may be useful.For example, set up a pure D-link at lowfrequencies and a constant D-link at higherfrequencies. This parameter is used with par.1-00 Speed closed loop [1] control.7-06 Speed PID Lowpass Filter TimeRange:1.0 - 100.0 ms * 10.0ms* default setting ( ) display text [ ] value for use in communication via serial communication port208 MG.33.B6.22 - VLT is a registered Danfoss trademark
