Overview

Task

Due to cascaded processing in the NC channel there is a time delay between decoding an NC program and executing the motion blocks in the interpolator. This means that decoding always precedes execution.

With HSC programs this look-ahead function may involve several hundred motion blocks. In addition, changes initiated by the user in the NC program may only become effective with a time delay.

By limiting the decoder block ahead function the reaction time to program influences can be shortened.

Properties

With certain technologies, such as flame or water-jet cutting, the user can adapt specific process parameters by using variables, e.g. feed rate in the running NC program.

When the block-ahead limit is active, it means that these changes become effective rapidly and are included timely in the cutting process.

Parametrisation and programming

Two types of block ahead limiting can be activated:

1. By configuration in the channel list, whereby block-ahead limiting becomes immediately effective at program start.
2. By programming in the NC program, whereby block-ahead limiting can also be activated only for specific program parts.