Description

Program start in block search mode

In block search, a specific program point, which is called the continuation position, is controlled without real axis motions. After this program point is reached, the axes are positioned at the contour either manually or automatically and the machining process is continued.

Continuation position

The continuation position is the position at which processing the NC program ends in block search and real machining starts on the workpiece.

Normally this is the interrupt position of a previous machining process. The reason for an interrupt may be to measure a workpiece or a tool breakage.

Continue in a motion block

The continuation position may also be located within an NC block. For this reason, one option with all block search types is to define the covered distance in the NC block as of which actual machining should continue.

Block search must be selected on the control panel (HMI) or via the PLC before the main program starts. Block search selection is modal, i.e. it remains active after the NC program ends. Block search must then be deselected explicitly, e.g. via the HMI.

Simulation and axis motions

No physical axis motion takes place in block search mode up to the continuation position. However, the NC program is completely decoded to produce the required program context at the continuation position.

Since no real interpolation takes place, the continuation position is usually reached very much faster than with normal program processing.

Simulation and technology functions

In block search mode, the PLC receives all technology functions as in normal mode so that machine functions can be switched correctly. These functions must also be acknowledged.

The PLC synchronises the selection/deselection of block search mode. This may result in the specific handling of certain technology commands if this is supported by the PLC (group handling, activating certain functions before block search is deselected).

This extension is available as of Builds V2.11.2018.09, V2.11.2804.10 and V3.1.3030.2.

Move to continuation position

When the continuation position is reached in block search mode, ensure that the axes were moved from their current actual positions to the restored command positions before actual machining starts (Restart to the contour)

At the same time, the spindles must reach their last commanded speeds.

Real mode

After switching over to real machining, the NC program continues as if it had been started without block search mode. A number of methods are available for restart to the contour (see Restart to the contour after block search).