HEIDENHAIN iTNC 530 HSCI - Finding position differences of direct and indirect encoders

6 – 68 HEIDENHAIN Service Manual iTNC 530 HSCI
There are peaks in the Pos.Diff. signal when the direction is changed during braking and acceleration.
Between the rotary encoder in the motor and the scanning head at the table there are coupling
systems (belts, gears, couplings) and the mechanics (recirculating ball nut, guideways, etc.)
The machine at which the recording was made features a belt drive.
It can also be seen that the Pos.Diff signal increases and decreases depending on the traverse
direction. This behavior is due to an inaccuracy in the transmission ratio of the drive (e.g. belt, ball
screw).
Conclusion Ideally, you have older recordings of the machine which you can now compare with the new ones.
If the position difference has increased, in most cases improvements of the mechanics or the
coupling system are required.