Description

The precalculation of future data elements function provides users with a prediction of future date elements at a configurable future point in time starting from the present point in time.

This function is activated by P-STUP-00070:

configuration.channel[0].interpolator.function FCT_DEFAULT | FCT_CALC_STATE_AT_T

Depending on the mode setting (P-CHAN-00325), the function permits the precalculation.

Mode 1: Precalculation of path velocities at up to 10 future points in time

Mode 2: In addition to the path velocities of Mode 1, the axis positions, velocities and accelerations of all axes located in the channel are precalculated in the first time entry.

Precalculation of path velocity

The results for future path velocities can be read by CNC objects (ESA pathfeed).

Precalculation is limited to the look-ahead function. If no prediction is possible for path velocity planning (time offset too great), the value -1.0 is output.

Notice

If the result -1 is output for future path velocity, no value could be calculated.

Adapt the look-ahead buffer by P-STUP-00071

As of CNC Build V3.3104.08 future path velocities can also be read over the HLI interface. The data element esa_data_valid indicates whether the future data element is valid.

Precalculation of an axis state

The results of these calculations are also contained in corresponding CHC objects to precalculate the axis position, velocity or acceleration of axes. Only the value of the first time entry is used to precalculate at axis level.

The first time entry is defined by P-CHAN-00324 (esa.time[0]) or by #CHANNEL SET [ESA_TIME0=…].

As of CNC Build V3.3104.08 future axis states can also be read over the HLI interface. The data element esa_data_valid indicates whether the future data element is valid.

Recommendation for look-ahead buffer

Setting for the available look-ahead buffer (P-STUP-00071):

configuration.channel[0].interpolator.number_blocks_lah 500