6.8 Servo Gain Adjustment Application Function6-536 Adjustments6.8.2 Force FeedforwardThe force feedforward function is valid only in speed control and position control.The force feedforward function shortens positioning time, The host controller differentiates a speed referenceto generate a force feedforward reference, and inputs the force feedforward reference together with the speedor position reference to the SERVOPACK.(1) Connection ExampleConnect a speed reference signal line to V-REF (CN1-5 and -6) and a force feedforward reference to T-REF(CN1-9 and -10) from the host controller.(2) Related ParametersForce feedforward is set using the parameters Pn002, Pn400 and Pn415.The factory setting is Pn400 = 3.0. If, for example, the force feedforward value is ±3V, then, the force is lim-ited to ± 100% of the rated force.Note 1. Too high a force feedforward value will result in overshooting or undershooting. To prevent such troubles, setthe optimum value while observing the system responsiveness.2. The force feedforward function cannot be used with force limiting by analog voltage reference.• The following settings are required if model following control is used together with the speed feedforward(V-REF) input and force feedforward (T-REF) input.-V-REF (CN1-5)PositionreferenceKp Pn100 Current loop MEncDiffer-ential KFFSpeedcalculationIntegration(Pn101)+ ++++T-REF (CN1-9)LinearservomotorLinear scaleHost controller SERVOPACKKp: Position loop gainK FF : Feedforward gain+ + Pn400Pn300Pn415-DividerParameter Function When Enabled ClassificationPn002 n.0 Disabled After restart Setupn.2 Uses T-REF terminal for force feedforward input.Pn400Force Reference Input Gain ClassificationSetting Range Setting Unit Factory Setting When Enabled10 to 100 0.1V/rated force 30 Immediately SetupPn415Filter Time Constant ClassificationSetting Range Setting Unit Factory Setting When Enabled0 to 65535 0.01 ms 0 Immediately SetupParameter Function When Enabled ClassificationPn140n.0 Model following control is not used together withexternal speed/force feedforward input. Immediately Tuningn.1 Model following control is used together with exter-nal speed/force feedforward input.Speed Position ForceSpeed Position Force
