4/11/2024 6:21 AM | |
Joined: 11/4/2011 Last visit: 8/15/2024 Posts: 230 Rating:
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Hi there, if this was happening all the time, my guess would be some wrong invertion of the encoder, so that the axis tries to do position control, but intertpretes the actual movement in the wrong direction. But as you say this only happens randomly, this can't be it. Best you configure a trace recording to be made. Ensure to set the sampling of the recording to OB MC-Servo (so that you capture every value in the same cycle as the TO processes it). My guess would be to record the following parameters of the TO: Velocity, ActualVelocity, VelocitySetpoint, Position, ActualPosition, ErrorDetail.Number, StatusWord, StatusPositioning.FollowingError. Maybe the hardest part then is to find a trigger condition, which ensures to record this specific situation, and not just everything. It's up to you to think of something suitable (either existing or to be added to the program). EDIT: For the TO you can configure where it expects the encoder value to have its overflow. Since some versions, the default parametrization in the TO is to expect the overflow in the encoder raw value (Gx_Xist1 in the telegram) at 2^32-1 bits, i.e. it expects the encoder to use all 32 bits of the Gx_Xist1 slot in the telegram, as specified by the PROFIdrive norm. But some encoders don't do this. Instead they overflow earlier. If your encoder now overflows not after 32 bits but after 30 bits (its resolution), but the TO expects overflow after 32 bits, the TO will interprete this overflow not as a regular overflow but as position jump. In consequence the position control will lead to such movements. See also here in the documentation, section "Evaluation of incremental actual value Gx_XIST1 with absolute encoders": https://support.industry.siemens.com/cs/ww/en/view/109817884/158541876619 To check this, either check your encoder's manual or contact the manufacturer. You could also do a trace recording of the Gx_Xist1 value in the telegram and check where the value overflows to/from zero. Regards, |
Last edited by: daviso at: 04/11/2024 06:33:09Last edited by: daviso at: 04/11/2024 06:34:48 |
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