# True Angle Compensation

Certain tools can detect and measure the tool rotation during tightening. If the tool is rotated during tightening, the angle measurement may be corrupted. This may lead to a faulty tightening if the tool movement is too great. For variations within specified limits, the controller can compensate these rotations and make a correct tightening.

This is an additional Licensed Feature, available per Virtual Station.

If the tool rotation is outside specified limits during the tightening, the tightening is aborted and NOK is reported. Additional information reports Tool movement exceeded.

True angle compensation limits
Parameter | Description | Default
--- | --- | ---
Negative angle limit | Defines the maximum negative rotation of the tool. If the value is exceeded the tightening is terminated and an error is reported. This is expressed in a numeric angle value. | Enabled, value set to -30 degree
Positive angle limit | Defines the maximum positive rotation of the tool. If the value is exceeded the tightening is terminated and an error is reported. This is expressed in a numeric angle value. | Enabled, value set to +30 degree

STB tools do not have the capability to measure the tool movement. If the True angle compensation is set to On, the error message Invalid Tightening Program will be displayed together with the additional information Feature not supported by the tool.