Configuring a Controller for a Stepper System or a System with No Motor

NI Motion Measurement & Automation Explorer

Configuring a Controller for a Stepper System or a System with No Motor

  1. Power on all of the hardware in the motion control system, taking into consideration the order in which you must power on the devices.
  2. Launch MAX and verify the motion controller firmware is updated.
    Tip  This step is not applicable if you are using the NI SoftMotion Controller.
  3. Select a configuration.
    1. Expand Devices and Interfaces in the configuration tree.
    2. Expand NI–Motion Devices, and then select the appropriate device.
    3. Click Default xxxx Settings to display the configuration options.
    4. Select Open Loop Stepper.
    5. If you want to customize any of the device settings, use the configuration tree items under each axis below Default xxxx Settings to view and configure items per axis, or for all axes.
      • To configure all of your axes at once, select the top-level item for each configuration tree item below the Default xxxx Settings item, and configure the controller settings as appropriate. Click Save to save the customized settings to the MAX database.
      • To configure the axes individually, expand the top-level item for each configuration tree item below the Default xxxx Settings item. Select the axis you want to configure, change its attributes, and click Save.


      If you do not want to customize the device settings, initialize the controller.
      • Axis Configuration—Use the Axis Configuration tab to control the basic nature of your axis or axes, such as the type of motor or feedback device.
      • Motion I/O—Use the Motion I/O tab to configure various aspects of the I/O conducted during the move, such as limits and switches.
      • Trajectory Settings—Use the Trajectory Settings and Move Constraints tabs to set up various aspects of the move, such as operation mode, velocity, and following error.
      • Find Reference Settings—Use the Find Reference Settings tab to set up home, index, forward, reverse, center, and sequence references for the move.
      • Gearing Settings—Use the Gearing Settings tab if you are gearing an axis to another axis or an encoder.
      • Control Loop Settings—Use the Control Loop Settings to set up PID loop parameters and filters.
      • Compare & Capture Settings—Use the Compare & Capture Settings tab to set up high-speed captures and breakpoints.
      • Digital I/O Settings—Use the Digital I/O Settings tab to set up port polarities and directions for the controller as it is connected to other devices.
      • ADC Settings—Use the ADC Settings tab to configure the analog inputs on the controller.
      • Encoder Settings—Use the Encoder Settings tab to configure the encoder settings for the system.
      • PWM Settings—Use the PWM Settings tab to configure the Pulse Width Modulation (PWM) output settings for the motion controller.
    6. If you customized any of the controller settings, click Save on the MAX toolbar to save the changes to the MAX database on the local machine. If you want the changes to apply to all of the axes, click Save to All Axes on the MAX toolbar.
  4. Click Initialize on the MAX toolbar to send the saved controller settings to the controller. Initializing the motion controller resets it to a known starting state so that it is ready for commands.
  5. Turn the motors by hand to check for holding torque. Motors that hold firmly in place exhibit holding torque, indicating that they are powered and responding to commands from the motion controller.
  6. Perform a single-axis test.
    1. Double-click the Interactive item in the configuration tree.
    2. Expand the 1-D Interactive item in the configuration tree.
    3. Enter 10000 in Target Position.
    4. Click Apply just below Target Position.
    5. Click Start on the toolbar. As the motor rotates, Position increases to 10,000. Position changes to 10,000, regardless of whether a motor is attached.
    6. Click Kill on the toolbar to allow the motor to rotate freely.
    7. Turn the motor by hand. Notice that Position does not change. Stepper motors operating in open-loop mode cannot read a change in the position of the motor.
    8. If you have encoders on the stepper motor, continue with the following steps. If you do not have encoders on the stepper motor, you are finished with the device configuration.
  7. Change the motor type to closed-loop stepper.
    1. Select Default xxxx Settings in the configuration tree.
    2. Select the Closed Loop Stepper option button.
    3. Set the values for Encoder counts per revolution and Stepper steps per revolutions. Refer to the motor or encoder documentation for the values.
    4. Click Save on the MAX toolbar to save the changes to the MAX database on the local machine.
    5. Click Initialize on the MAX toolbar to initialize the motion controller.
  8. Perform a closed-loop stepper test.
    1. Click 1-D Interactive in the configuration tree.
    2. Click Apply at the bottom of the window.
    3. Click Kill on the toolbar.
    4. Rotate the motor by hand. Position changes as you turn the motor.