RobotStudio event

Warning 80002 "Tracking Sensor NOT Connected" [ArcWelding PowerPac]

Dear sirs,

in the event log i get the warning: "Tracking sensor NOT connected (Error Code 80002).
(Category: user)
The strange thing is, that the sensor is working well and can be controlled from the robot controller.

If we start a welding process with tracking he aborts and throws the error message : AW_TRACKSTA_ERR. If we use the error handler and restart it, it works fine the whole process.

Any hint, how to find the source of the error?

Thank you very much!

Yours

Peter