Motor Errors

After completing each movement action of the tuning stubs, the Autotuner internally records the current positions of the stubs in terms of motor steps, starting from the reference (zero-extension) positions. Occasionally, a discrepancy may arise between the counted steps and the actual positions of the tuning stubs, commonly known as “lost steps.” If left unattended or allowed to accumulate, this discrepancy can negatively impact autotuning accuracy. Moreover, commanding the stubs to go to a zero or a near-zero extension can result in hitting one or more of the terminal switches. In such instances, the Autotuner reports a motor error, causing it to cease responding to motor movement commands. In the Tuner View window, the affected stubs will be highlighted red.

Listed below are several reasons for losing motor steps, along with possible remedies:

  • Autotuner turned OFF during stubs movement: Non-fatal. Remedy: Reset the stubs using the All Stubs Home procedure, either through the corresponding button or a command.

  • Autotuner operated at low temperature (below 5°C): Non-fatal. Remedy: Increase the ambient temperature, then reset the stubs using the All Stubs Home procedure.

  • Autotuner subjected to strong mechanical vibrations: Non-fatal. Remedy: Isolate the unit from vibrations, then reset the stubs using the All Stubs Home procedure.

  • Failure of a stepper motor or its control/driver electronics: Fatal. The affected stubs do not respond to All Stubs Home attempts but otherwise seem intact. Repair in the factory is necessary.

  • Damage caused by arcing: Fatal. Repair in the factory is necessary.

  • Occasional motor errors without an obvious reason: Run Tuner Test to assist in making further decisions.

It is good practice to invoke the All Stubs Home procedure upon Autotuner power-up. This can be achieved by editing the following line in the Homer internal Tun.cfg file:

PowOnAction=1

or (the default setting)

PowOnAction=2