Siemens SINUMERIK 808D Programming And Operating Manual page 117

Activation by setting machine data
MD20150 $MC_GCODE_RESET_VALUES[22] = 2: CDON (effective modal)
MD20150 $MC_GCODE_RESET_VALUES[22] = 1: CDOF (not effective modal)
Function
With active CDON (Collision Detection ON) and active tool radius compensation, the control system monitors tool paths
through look-ahead contour calculation. This Look Ahead function allows possible collisions to be detected in advance and
permits the control to actively avoid them.
With deactivated bottleneck detection (CDOF), a search is made in the previous traversing block (at inside corners) for a
common point of intersection for the current block; if necessary the search is extended to even earlier blocks. An error
message is triggered if no point of intersection is found with this method.
Collision detection:
CDOF can be used to avoid the faulty detection of bottlenecks, resulting, for example, from missing information that is not
available in the NC program.
Note
Machine manufacturer
The number of NC blocks that are included in the monitoring can be set via machine data (see machine manufacturer).
Examples
In the following pages, you will find a few examples of critical machining situations that can be detected by the control
system and corrected through changes in the tool paths.
To avoid program interruptions, during program validation only the ones that have the biggest radius from among all tools
should be selected.
In each of the following examples, a tool with a too large radius was selected for machining the contour.
Programming and Operating Manual (ISO Turning/Milling)
117
01/2017