RobotStudio event

Why can't use MOVEJ when using Conveyor Tracking

As mentioned in the title,when I wanted to use MOVEJ in conveyor tracking,it failed to do that.
There is a trouble shooting#50172(MOVEJ not allowed) ,which is shown below.

I've looked for reasons in manual but still don't know why MOVEJ is not allowed with wobj coordinated with external position mechanical unit.
Is it the nature restriction of MOVEJ?
I know that MOVEJ is not for tool to go straight line,but when I want to pick something up from the conveyor,
why can't I move the tool to the position that above the work object by MOVEJ and take it up by MOVEL?

Thank you in advance for your help.


  • Hello, 
    why don't you do the moveJ in a workobject which is not attached to the conveyor and then for the picking motion instruction you use the cnv wobj?
  • Thank you for your advice. :)
    But then the position for MOVEJ to go will be a constant point,and it would not be able to follow the object.
    For example,if the point I set for MOVEJ to go is far from the start-machining point of the next object(determine by the starting window),
    then the MOVEJ path will be meaningless because it doesn't assist the robot move to the target faster.

  • Neily03
    Neily03 ✭✭✭
    MoveJ is meant to a constant point with specific axis positions, if cant do that relative to a moving work object.

    For example you cannot set axis1 to 60 degrees and keep it there while following a moving object, its impossible.  Like tying to chase a ball without moving your legs.
  • Hi everyone! 
    I am a very new person to ABB robot. In my opinion, Wobj coordinate system is fixed. But i'm not sure, and i still wonder that Wobj is fixed in comparison with Base coordinate system or other coordinate system? And when the robot moves (like sliding on a linear motion guide system), will Base coordinates system and Wobj still fixed???
    Could anyone help me make it clear or recommend some documents about this problem!
    Thank you all in advance!
    P/s: I posted a question in our forum but noone replied :( . So plz help me if you know, thank you all very much!