Unknown error on Palletizing robot after E-Stop

  • I was running through machine recovery testing with a customer on a new piece of machinery and got a strange error on the robot pendant I haven't seen before after pressing an E-Stop when the robot was mid-movement (linear move).


    There was a popup message titled "Jogging", that said "The current coordinate system was changed, because the selected kinematic group does not support it. \n Old value: Tool \nNew value Axes"


    The error message was "KSS03275 - Positioning motions to PalMode only allowed with individual PTP and SPTP blocks."


    I was able to recover by switching to Teach, acknowledging the error then switching back to Ext and continuing, but this customer wants to normally have their pendant removed so hoping to avoid this error. On subsequent E-Stops the message would come up but not the pop-up, and it could be recovered from the PLC. May never happen again, but I am curious about the root cause of this. Any insight would be appreciated.


    The robot is a KR120 R3200 PA (KRC4 NA UL controller), running system software 8.5.8. Tech packages:

    BoardPackage=1.4.1

    DiagnosisSafety=3.0.0

    GripperSpotTech=4.1.4

    KUKA.DeviceConnector pre-installed=2.1.2

    KUKA.EtherNetIP MS=3.1.4

    KUKA.UpdatePackageFirmware=1.0.3

    KUKA.UpdateService=1.1.6

    KUKA.UpdateServiceConfiguration=1.0.6

    LoadDataDetermination=7.0.3

    SafeOperation=3.4.4

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  • For me that sounds like a problem with positioning back onto the commanded path after being kicked of from it due to the emergency stop not being handled path preserving. This usually triggers a ramp stop leaving path tangential. If your robot is a 5 axis palletizer this can lead to losing palettizing position by a to far drifting axis 5. At least the comment on $Palmode in the error message suggests this.


    For further clarification it would be helpful to know the motion type the robot was in when emergency stop was triggered.


    Fubini

  • Thanks for the replies.


    The robot was executing a LIN move when the E-Stop was triggered.


    I have tried E-Stopping again on the same path and it did not occur again (only 1 attempt, trying to run production on the machine so can't spend too much time on this). This robot has very large tooling that will be exerting a high moment on the 5th axis at this point in the path, so I wouldn't be surprised if it had failed to maintain its path, I didn't check the status of that System Variable when this message was active.

  • PalMode -- is this a 6-axis robot configured to operate as if it were a 4-axis palletizer? That might be the issue -- if the E-Stop forced A5 to move outside of the envelope acceptable for Palletizing Mode.

  • old palletizers were 4 axis

    with Quantec, 5-axis palletizers were introduced (and here it was mentioned KR120 R3200 PA).


    they have A5 but it is linked with a3 through software instead of external mechanical linkages. this makes it possible for robot to operate in tighter space (low ceiling for example). also much nicer for maintenance...


    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

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