No announcement yet.

Cannot get gripper / manipulator current position readings

  • Filter
  • Time
  • Show
Clear All
new posts

  • Cannot get gripper / manipulator current position readings

    Hey everybody,

    I have the same problem as described in this thread but I don't want to resurrect such an old thread:

    I can control the electric robot arm (aka gripper aka grappler aka manipulator). But I cannot get readings of the current position of each axis. I get an error code of "-1" which isn't even specified in the help...
    What seems to be related to this problem is the fact that "position reached" of the position selection never returns true. And when I store a position of the robot arm, all axis values are 0. Any ideas on how to fix this problem?

    Best regards

  • #2
    To add to that:

    When connected via SSH, "robtopic echo grappler_readings" returns:
    10:41:33.007 | grappler_readings
    *** channel=0 id=1 found=true ***
    angle=0 speed=0 error=0
    cwAxisLimit=24.1758 ccwAxisLimit=74.1978
    *** channel=1 id=1 found=true ***
    angle=0 speed=0 error=0
    cwAxisLimit=8.52747 ccwAxisLimit=70.9451
    *** channel=1 id=2 found=true ***
    angle=0 speed=0 error=0
    cwAxisLimit=9.49451 ccwAxisLimit=67.4286
    *** channel=1 id=3 found=true ***
    angle=0 speed=0 error=0
    cwAxisLimit=47.7363 ccwAxisLimit=52.3956


    • #3
      Okay, I just restarted the grappler daemon and now it works. What caused the daemon to fail? How can I prevent this in the future?
      And the error code of the axis readers is still "-1". What does this value mean?
      Last edited by aljosha; 01-27-2022, 12:58 PM.