Feedback Topic

Use the Feedback topic to configure feedback and encoder-related parameters. This topic and its modules are in the Axes category of the Configure workspace in Automation1 Studio.

IMPORTANT: When you use a helper module to edit parameters automatically, make sure you are in Basic Editing mode. To edit parameters manually, click Go to Advanced Editing on the top right of the Configure workspace.

Automatic Encoder Tuning Module

Use the Automatic Encoder Tuning module to tune encoder signals for optimum performance. Refer to How to use the Automatic Encoder Tuning module to learn how to use this module.

When you use the Automatic Encoder Tuning module, the module moves the axis and collects data to determine the optimal encoder gain, offset, and phase parameters. The module calculates an applicable distance and velocity for the tuning motion profile. After this process is completed, the encoder gain, offset, and phase parameters are applied to the controller.

IMPORTANT: Use this module only with analog feedback devices.

  1. In the Axes category, select the Feedback module, and make sure that you have the Automatic Encoder Tuning tab selected.

  2. Make sure you are in Basic Editing mode.

  3. Enable the axis that you are tuning.

  4. Click the Start button.

  5. Click Save All on the left panel of the Configure workspace to save the parameter changes to the controller. This will keep the parameter changes active if you reset your controller at a later time.

IMPORTANT: When you set up a system for the first time, tune encoder signals before you use the Servo topic modules to tune your servo loop. It is possible for the servo gains and filters configured by Machine Setup to supply a servo loop that is not stable. If this occurs, this module might not command the necessary motion to tune the encoder signals automatically. Refer to the Manual Encoder Tuning Module section for information about how to tune encoder signals without commanding motion.

Tip: To tune the encoders for the gantry spars, use the Axis drop-down box to select the name of the Linear (R) gantry axis or the name of the Yaw (Theta) gantry axis. The Automation Encoder Tuning module always commands motion on the R axis and tunes the encoders connected to each gantry spar.

Manual Encoder Tuning Module

Use the Manual Encoder Tuning module to adjust encoder gain, offset, and phase parameters and examine their effect on the Lissajous pattern. Refer to How to use the Manual Encoder Tuning module to learn how to use the module.

  1. In the Axes category, select the Feedback module, and make sure that you have the Manual Encoder Tuning tab selected.

  2. Make sure you are in Basic Editing mode.

  3. Enable the axis that you are tuning.

  4. Click the Tune Encoder Parameters button to collect data and determine the optimal encoder gain, offset, and phase parameters.

  5. Click Apply Changes to apply the encoder gain, offset, and phase values to the controller.

    1. If the Lissajous pattern is satisfactory, click Save All in the Configure workspace. This keeps these parameter changes active after your next controller reset. You are finished with this procedure.

    2. If the Lissajous pattern is not satisfactory, continue to Step 6.

  6. Click Collect Snapshot or Collect Continuous to collect data and show the Lissajous pattern.

  7. Make sure that the axis is moving.

    1. If the Enable Motion toggle is on, the axis will move back and forth at a distance and speed determined by the Number of Encoder Cycles that you enter.

    1. If the Enable Motion toggle is off, you must manually move the axis while tuning the encoder parameters.

  8. Manually adjust encoder gain, offset, and phase parameters and compare the Lissajous patterns.

    1. You are trying to tune the feedback device so that its Lissajous pattern closely matches the ideal Lissajous pattern. You do not want the Lissajous pattern of the feedback device to go outside of the ideal pattern.

  9. When the Lissajous pattern of the feedback device closely matches the ideal Lissajous, click Stop to stop the tuning cycle.

  10. When the calculation of the feedback gains is finished, do a check of the Lissajous pattern over the full length of travel of the axis. You can see the Lissajous pattern (without tuning) by collecting data in the Data Visualizer module.

    1. If at some position the Lissajous becomes much larger than the ideal Lissajous, repeat the tuning procedure with the axis located at this position.

    2. If the Lissajous pattern is satisfactory, click Save All in the Configure workspace. This keeps the parameter changes active after your next controller reset. You are finished with this procedure.

Tip: To tune the encoders for the gantry spars, use the Axis drop-down box to select the name of the Linear (R) gantry axis or the Yaw (Theta) gantry axis. The Manual Encoder Tuning module collects data and tunes the encoder parameters for the selected axis. The Manual Encoder Tuning module always commands motion on the R axis.

Advanced Editing

If you must edit the Feedback parameters manually, click the Go to Advanced Editing link. Advanced Editing contains the parameter modules that follow:

  • Feedback
  • EnDat Encoder
  • SSI Encoder
  • BiSS Encoder
  • Multiplier
  • Auxiliary Multiplier
  • Cap Sensor

Related Help Pages 

Axes Category Overview

Parameters