position register changing representation

    Good day,


    I've got a weird one that I'm hoping someone can help me with. I have user frame values stored in PRs. I get a call saying they are getting a 'position not reachable' alarm. I looked at PR[1] and while it has the same numerical values, it has somehow gone from Cartesian coordinates to joint angles. As far as I know, the only two ways to change the representation of a PR is either manually on the TP or by doing PR[X]=JPOS. Nobody touched the TP and we do not use JPOS instructions at all. Are there any other ways for a PR to programmatically change representation from Cartesian to joint?


    Thanks,
    Lei

    Quote from leidai5

    "Nobody touched the TP ..."

    How can you know that? Users always say this.

    Is it a single-time incident or repeated issue?

    Do you have anything like PalletTool or PickupTool in the robot? These may use PR[1} for own purposes.

    I would avoid such address anyways, as it is the first one you see in the Data screen, hence the most subject to erroneous overwriting.

    Yes, fair point but I looked at recorded camera footage and there was indeed nobody around the TP at the time it happened.


    It did happen once last year, at which time I thought it must have been someone's fat fingers. However, the number of key presses made the chances of it being accidental very unlikely.


    We do not have PalletTool or PickupTool.

    Hello leidai5,

    Quote

    As far as I know, the only two ways to change the representation of a PR is either manually on the TP or by doing PR[X]=JPOS

    The representation of a Posreg can be changed with a Karel-Prog too.


    AND

    using a command like

    PR[1]= UTOOL[1]

    will change the Reprentation to the type "POSITION"

    you see something like NX, NY...

    ..

    Thanks for the ideas.

    We don't use any KAREL programs on this robot.


    The only instructions that involved PR[1] are:


    33: UFRAME[1:User Frame]=PR[1:L1 User Frame] ;

    34: UFRAME_NUM=1 ;


    So we copy the contents of PR[1] into UFRAME[1] but nothing writes into PR[1].

    We used to run into that on occasion. If I'm remembering right, I think it was happening only with PR[1] for us and may have had something to do with PR[1] specifically. It was something that only happened a couple times a year.

    Yea, this only happened a couple of times in the past year and only with PR[1]. Sounds like we should just avoid using PR[1]. Should be an easy enough change. Thanks!

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