◆ ClosedLoopStepperSet()

virtual void ClosedLoopStepperSet ( bool  enable)
pure virtual

Enable or disable Closed-Loop Stepper support (custom firmware required).

ℹ This function is avaliable in RapidCode and RapidSequencer

ClosedLoopStepperSet will enable or disable closed-loop stepper support.
enableTrue = closed-loop stepper, False = open-loop stepper.
Sample Code:
// configure the axis to have closed-loop stepper control
  • SynqNet controllers support open-loop stepper motors via digital step and direction synthesis. In open-loop mode, the step and direction values are calculated from an Axis trajectory calculator. This new option provides closed-loop stepper control by taking the output from a filter (usually applied as velocity or torque voltage), and converting it to velocity. These velocity values can be used by the SynqNet step and direction synthesis engine.
  • This method requires custom firmware (option 98) to be loaded on the controller.
  • Closed-Loop Stepper firmware requires the use of the "Amp Enable" circuitry on the RMB for safe operation.
  • Standard PID and PIV algorithms are supported.
  • Velocity Feed Forward is the most important parameter. Vff should be set to the value of the ratio between motor steps to encoder counts. For example, if your rotary motor has 8000 motor steps per revolution, and 2000 encoder counts per revolution, Vff should be 8000/2000 = 4.0.
  • Experience shows that greater stability is possible when the ratio of motor steps to encoder counts is greater than 4.0.
  • If Vff is set correctly and zeros are entered for Kp, Ki, Kd, the motor should work exactly like an open-loop stepper motor. (This is a good test.)
See also