Hello guys,
I have project with one robot and 3 external axes. Target is make movements with external axes independent of the robot's movements.
Just create two parallel task - one will control robot and second will control external axes. Routines I will call from PLC on ProfiNet.
With ABB robot I will just make second task where I will make program for control of external axes but with KUKA I have no idea. 
you can only control external axes from the main "task" or more generally called in this forum "submit".
The main submit is allocated by default to sps.sub and from there you can if needed control external axes. None of the extended submits can be used for this purpose.
Depending on what you want to achieve might be able to do this from the regular robot interpreter. When you use the axes as asyncronous the motion command asyptp commands are non blocking. And the run pointer just flies over them without waiting for them to finish.
Using sps.sub is also fine but maybe tricker to control as you need to manage that you do not stack more than 3 asyptp ontop of each other. But either way is doable..
Look for manuals external kinematics, system variables and system integrators manual for a relevant kss version in your case. These are all found in the kuka xpert portal.
