Robot stopping in AUT without error and disables the Drives

  • Hello guys,


    I am running my program in AUT mode for a continues running cycle. It runs completely one loop cycle to a certain point in middle of the loop and then it disables the drives without any error. There is only one message which comes very fast it being clear in less than one second. After several time trials, I found out that the message is Operator Safety.. and exactly the operator safety is disabled.

    The strange thing is that the certain point, depends on the speed of the robot running speed. It means that stopping point is 30 percent is different by 50 percent. More strange is that, there is not stopping in 10 percent.

    The robot continues the program after enabling the drives and pressing the green arrow.


    Also I have another problem. Why the robot program is not running in AUT mode out of the loop without keeping the safety key?


    Any idea of disabling the Drives reason?

  • Check the wiring, I suspect robot movement causes some vibration making the wires disconnect for a moment.

    Yes this might be the case.

    We had a similar issue when the RDC plugs had not been connected properly and kills the motion enable right after a sec or two.

  • I doubt it be wiring. There is no contact from the robot with area.

    The project which I am programming in has been defined before and I am not familiar with project defining and safe area defining with KUKA robot. Just in case, could the reason be a safety area defined in the robot cage so that the robot speed is not allowed to be higher than a certain amount?


    If yes, anyone can guide me how to check or define a new safety area?

  • Yes that could be a possibility. But since you do not know how to change safety configuration is probably a sign you are not allowed to do them. You need special certificates and user rights for this.


    Having said that you can open safety configuration from the menu. Where it is located exactly differs in software versions. Since you did not provide this relevant information you have to search yourself.


    This clearly shows how important it is to provide as much info about your setup as possible. Otherwise you will not get competent answers.


    On the other hand I would think it unlikely. If it is the case of a safety violation you see a quite message. Even if you do automatically reset them you should still be able to track them down in the logbook.

  • I am also wondering why the message is not remaining. The controller is clearing the message right away after declaring. It's like the message is declared for under half a second. Why is it being cleared?

    Is the log being stored some where? To see if there are further information in the log.

  • Quote

    Ok. I found the log.

    It is a Safety open.


    maybe .... but did you REALLY read the log? there are some other messages too. order of message is VERY important. several messages may have nearly the same time stamp. this is result of a burst of messages within 0.5 - 1 sec for example. and many (most) of those messages are just result of something previous such as another message. in other words, mere PRESENCE of the message does NOT guarantee that what message displays is a REASONABLE concern.


    so... i would be focusing on IDENTIFYING blocks of messages that occur together in a burst.. then look for FIRST message within that block.

    yes "Operator safety open" is in the block and it is repeated but... is that REALLY the message that started it all?


    what if the first message is No motion enable present? that would point on bad logic in PLC, rather than hardware error in the robot and you would be chasing wrong lead (and likely get increasingly more frustrated if issue persisted)... which is exactly why reading is important.

    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

  • Looking at the time stamp of the Errors, I found out that the periodic errors are as following:

    1- Operator safety open

    2- No motion enable present

    3- Drives disabled by Safety.

    4- Drives have been discharged (reason:SAFETY)

    5- Dynamic braking active

    6- Drives off, intermediate circuit voltage still charged


    I am thinking on the idea wiring problem.

  • Hi guys. I found the problem.


    I would like to share my experience:

    We have a safety door which a sensor checks if it is closed and we have a press which when the press is clamping, the door vibrates and the sensors gives a very fast pulse. I increased the sensor range and the problem is solved.


    Thank you every body for your helps.

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