Robotstudio - Missing external axis value

  • Hello,

    Now I am working from home, so I try to get experience in RS.

    I have created our welding cell from a backup on my PC.

    An IRB 2400L and an IRBP500K positioner (IRC5).

    They are able to perform coordinated movements.

    Everything is fine, all programs are working well, what I have previously taught manually.

    But I am stuck with creating program in Robotstudio.

    The targets I have created, do not store the turning angle of the positioner, so when I try to run the program I get "Missing External Axis Value" event message. :frowning_face:

    Of course the positioner does not turn with the robot, when it should...

    The positioner should be turn to this position:

    I have tried to modify the extax values manually.

    Right click, modify extax and also tried overwrite robtarget in rapid, but I got further event messages I didn't understand.

    At the first target, I got "Position Outside Reach".

    It's not recognizable for me in this situation why.

    The first target is a simple movement, positioner turns to -150 degree, the robot axis 1 turns to the working area from safe position.

    I have taught similar movements manually several times.

    It could not be configuration problem...

    When I skip the first MOVE, an move PP to second movement, the robot and the positioner finally moves, but the position is different from the programmed position. :O

    Programmed position:

    Actual movement:

    I think something not OK with my targets created in RS.

    Or the method I have created them.

    When I teach robot from TPU (in reality), the robtarget always stores the actual positioner angle when I use 'wobj_stn' workobject.

    These robtargets are working fine in RS.

    I can run programs with coordinated movements (weld circular seams around the rotating axis of the stations).

    These are all manually taught programs...

    So I am confused.

    Thanks for your suggestions in advance.

    Best regards,


  • I start the procedure with 'ActUnit STN1'.

    Does it have the same effect?

    All parameters are 9E+09 in the robtarget, by the external axis. It doesn't matter how much is the actual angle...

    I will check your recommendation tomorrow... :smiling_face:

  • Right click your controller and select activate external axis, activate the appropriate axis (all three are only active during indexing, so typically you'd use STN1 or STN2)

    Thank You.

    It works.

    Now I already have extax values for the targets.

    I have modified the tartgets, and I will test it later.

    The 'position outside reach message' is still there at the first movement, and I still don't understand why...

  • I guess that you have a multitasking system.

    Here is some code I have done on a FlexArc Cell previously and maybe this will guide you a bit.

    Hope this helps.

    I have only one Task I use, but there are 2 more.

    My program is in Task1.

  • Tool at target is just graphical whereas the controller is... well.. the controller so any mismatch between them is usually calibration/setup related (TCPs baseframe etc)

    For example, it doesn't look like the tool coordinates are the same (hard to tell when you're using the show tool/robot at target).

    If you send me a pack'n go I can take a look at it.

  • There's difference between the shown welding torch and the tool.

    The welding torch is created from 3D model, it is the "theoretical" tool.

    The coordinate system you can see at the end of the torch is the actual TCP.

    It is synchronized from the backup...

    All my other program runs well nearly along the programmed position.

    For example:

    I have problem only with the targets I have created in Robotstudio.

    Later I will try to make a Pack&Go.

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