Pulse Configuration

Configuring the Motion Controller to Use Pulse Outputs

  1. Set the Amp Disable Action to NONE.
    The motor type cannot be set to STEPPER unless the Amplifer Disable Action it is set to NONE.


  2. Configure the motor Type for STEPPER.


  3. Set the motor's Stepper Pulse Width.
    When configuring the Step Pulse Width, make sure the maximum commanded velocity does not generate a pulse period that is less than 2x the pulse width. For example, if the maximum velocity is 100 kHz, the pulse width must not be greater than 5 microseconds.


    Maximum Velocity
    Maximum Pulse Width
    5 MHz
    100 ns
    2.5 MHz
    200 ns
    1 MHz
    500 ns
    500 kHz
    1 µs
    250 kHz
    2 µs
    100 kHz
    5 µs
    50 kHz
    10 µs
    25 kHz
    20 µs
    10 kHz
    50 µs
    500 Hz
    1 ms

  4. Enable the motor's Stepper Loopback if there is no encoder feedback.
    When using pulse outputs, the quadrature encoder inputs are still available. The position feedback information is not used to correct the pulse motor's position, but can be used by an application to monitor the actual position of the motor. If the encoder feedback is not in a one-to-one ratio with the step motor resolution, be sure to disable the position error limit action. If you do not have an encoder, the feedback can be simulated by enabling the motor's loopback feature.


  5. Configure the motor's Stepper Pulse A and Pulse B Ttypes.
    Pulse A and Pulse B determine the types of output pulses to be sent to a pulse drive. The most common examples are listed in the table below.


    Desired Output
    Pulse A
    Pulse B
    Step and Direction
    Clockwise and

  6. Select the motor I/O's Configuration Type for Pulse A and Pulse B signals.
    This will route Pulse A and Pulse B signals to the node's digital outputs.


  7. (Optional) Set the control algorithm to NONE for optimum firmware performance.



Pulse Configurations in Motion Console

Motor Object

Type Stepper (default is Servo)
Amp Disable Action None (default is Cmd = Act)
Step Pulse Width Value is determined by pulse drive specifications
Step Loopback Enable for open loop, Disable (default) for encoder feedback
Pulse A Type Configure for STEP, DIR, CW, CCW, QUADA, or QUADB
Pulse A Invert Enable or Disable
Pulse B Type Configure for STEP, DIR, CW, CCW, QUADA, or QUADB
Pulse B Invert Enable or Disable


In the screenshot above (SynqNet-RMB-10V2), you can configure Motor 0, XCVR A-F to be either Pulse A or Pulse B. Normally, two bits must be configured as Pulse A and Pulse B.

I/O Bit N Type Pulse A or Pulse B
(routes Pulse A signal to node's digital output)
(routes Pulse B signal to node's digital output)


Filter Object

Algorithm None (for optimum firmware performance)


MPI Example

See the sample application stepCfg.c for details.


MPX Example

Controller.Axis(0).MotorType = mpiMotorTypeStepper 
'AmpDisableAction set automatically when setting MotorType
Controller.Axis(0).StepPulseWidth = 0.000001 '1 us
Controller.Axis(0).StepLoopback = True
Controller.Axis(0).StepPulseAType = mpiStepperPulseTypeStep
Controller.Axis(0).StepPulseBType = mpiStepperPulseTypeDir
Controller.Axis(0).IoConfig(mpiMotorIo0) = mpiIoConfigPulseA
Controller.Axis(0).IoConfig(mpiMotorIo1) = mpiIoConfigPulseB
Controller.Axis(0).FilterAlgorithm = mpiFilterAlgorithmNone


See Also

Introduction to Pulse
MPX Axis Object Documentation



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