Cannot get gripper / manipulator current position readings

[aljosha]

Hey everybody,

I have the same problem as described in this thread but I don't want to resurrect such an old thread: https://forum.openrobotino.org/forum...rm-data-output

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
Aljosha

[aljosha]

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

[aljosha]

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?