Permissible calculation tolerance with forward / backward transformation (P-CHAN-00228)

P-CHAN-00228

Permissible calculation tolerance with forward / backward transformation

Description

Especially when self-created kinematic transformations are used (see @@[McCOM-TRAFO]), this parameter can maintain the required position consistency in the NC channel.

The result of the calculation sequence (Input values - Forward transformation - Backward transformation - Output values) must match the input values within specific limits.

Therefore, the CNC checks whether if these deviations are within the permissible tolerance according to the parameter and generates an error message if necessary. The default tolerance value here is 0.3 µm.

Due to internal algorithms (e.g. iterative solution method, numeric inaccuracies), this may lead to to greater deviations which then require adjustment using this parameter.

Parameter

permitted_trafo_deviation_limit

Data type

UNS32

Data range

0 < permitted_trafo_deviation_limit < MAX(UNS32)

Dimension

0.1µm or 0.0001°

Default value

3

Remarks

Setting large tolerances should be avoided since this may cause relatively large position jumps which can lead to the response of the dynamic monitoring function.

The standard tolerance value here should be maximum 0.5 microns.

Therefore, when self-created kinematic transformations are used, the internal algorithms must first be checked before setting excessive tolerance values.