FR-A701 INSTRUCTION MANUAL (Applied) - Automation Systems ...

Position control by vector control(2) Control block diagramRHRMRLREXSTFSTRCommandpulseJOGPr. 4 to 6Pr. 24 to 27Pr. 232 to 239Pr. 465 to Pr. 494travelPr. 7 Pr. 8(Pr. 44, Pr. 110)(Pr. 45, Pr. 111)Command pulse selectionPr. 428Position commandsource selectionPr. 419Multi-speed,communication 02Position commandacceleration/decelerationtime constantElectronicgearPr. 420Pr. 421Pr. 424Position feedforwardcommand filterPr. 425+-DeviationcounterPosition feedforward gainPr. 423Positionloop gainPr. 422 ++-Speed controlIMNPPr. 429Clear signalselectionDifferentiationEncoder(3) Example of operationThe speed command given to rotate the motor is calculated to zero the difference between the number of internalcommand pulse train pulses (when Pr. 419 = 0, the number of pulses set by parameter (Pr. 465 to Pr. 494) is changed tothe command pulses in the inverter) and the number of pulses fed back from the motor end encoder.1)When a pulse train is input, pulses are accumulated in the deviation counter and these droop pulses act as positioncontrol pulses to give the speed command.2)As soon as the motor starts running under the speed command of the inverter, the encoder generates feed backpulses and the droop of the deviation counter is counted down. The deviation counter maintains a given droop pulsevalue to keep the motor running.3)When the command pulse input stops, the droop pulses of the deviation counter decrease, reducing the speed. Themotor stops when there are no droop pulses.4)When the number of droop pulses has fallen below the value set in Pr. 426 In-position width , it is regarded ascompletion of positioning and the in-position signal (Y36) turns on.Motor speed [r/min]Command pulse frequency[PPS]Droop pulse valuePulse distributionMotor speedAccelerationDecelerationTimeStop settling timeLX signalServo onSTF (STR)Forward (reverse)Y36 signalIn-position signalPulse train Rough Fine Rough⋅ For conditional position control function by contact input, the STF and STR terminals provide the forward (reverse)command signal. The motor can run only in the direction where the forward (reverse) signal is on. Turning the STFsignal off does not run the motor forward and turning the STR signal off does not run the motor reverse.⋅ The pulse train is rough during acceleration and coarse at the maximum speed. During deceleration the pulse train isrough and at last there are no pulses. The motor stops shortly after the command pulses stop.This time lag is necessary for maintaining the stop accuracy and called stop settling time.REMARKS⋅ For the servo on signal (LX), set "23" in Pr. 178 to Pr. 189 (input terminal function selection) to assign the function.⋅ For the in-position signal (Y36), set "36" in Pr. 190 to Pr. 196 (output terminal function selection) to assign the function.116