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Autotuner 'Unexpected Amplifier State'

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I'm trying to use workbench for autotuning linear motors on AKD servo drives. For all three systems I have tried, I get the message "Drive is in unexpected amplifier state before writing tuning parameters: Amplifier Disabled unexpectedly" during the tuning process, and it is aborted.

What can cause this error? I do see the 'axis active' go red for a split second, and then come back on, just before the error message is given, but STO and other enable inputs are not changing, neither are any soft or hardware limit switches triggered.

p.s. I used to get an error on the direction during friction test, but setting gain margin to 16db and phase margin to 55deg solved that.




p.p.s. it looks like the drive disables at the moment it switches from torque mode to velocity mode during the tuning process

HanH - Mon, 11/05/2018 - 02:03
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1 Answer

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based on the problem description it looks like that you also have an external plc active.

In this case Workbench and the PLC are both trying to communicate to the drive and this can cause the described behavior.

For this reason disable the PLC and restart the drive or try to force the axis control word to 0 thus the Workbench can handle the complete communication.

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