i950 TA CiA402 Advanced and SSI rotary encoder: Tracking error spike on first release after power on (fixed from V01.06.04)

Corrected from:

TA i900: as of V01.06.04.2154

Response of the new version:

The torque jump previously observed during the first release after mains switch-on no longer occurs. Correspondingly, there is also no increased tracking error that could previously lead to the tracking error monitoring responding.

Notice:

The short-term remedy mentioned below is no longer applicable with this correction:

The mode of the position interpolation should be parameterised to "quadratic" again or remain set:

Interpolation mode 0x60C0 = quadratic [1] (recommended).

What happens?

When the inverter is enabled for the first time after switching on the mains (initialisation), a peak occurs in the tracking error curve.

This leads to a corresponding torque peak because the inverter tries to compensate for the tracking error or the tracking error monitoring responds when the tolerance is exceeded.

When does the behaviour occur?

i950 TA CiA402-Advanced with activated position control via the second encoder (application feedback) and

this encoder is an externally supplied rotary SSI encoder.

The described behaviour only occurs during the first enable after power on (initialisation).

Which products are affected?

TA i900: i950 TA CiA402-Advanced

Short-term measures / evaluation / recommendations:

As a short-term remedy, the position interpolation mode can be re-parameterised from "quadratic" to "linear":

Interpolation mode 0x60C0 = Linear [0].

The described behaviour does not occur with this setting.

Assessment of the effect of the corrective measure:

Quadratic position interpolation is actually advantageous over linear interpolation. However, the effects on the drive behaviour are rather marginal.

Automatic Translation

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/202100154/1/