Siemens SINUMERIK 840D sl Function Manual page 28

W1: Tool offset
2.3 Tool offset memory
Functions
Expansions to functions when assigning D numbers:
● The maximum permitted D numbers are defined via the machine data:
MD18105 $MN_MM_MAX_CUTTING_EDGE_NO (max. value of the D numbers (DRAM))
The default value is 9, in order to maintain compatibility with existing applications.
● The number of cuts (or the offset data sets) for each tool can be defined via the machine
data:
MD18106 $MN_MM_MAX_CUTTING_EDGE_PERTOOL (max. number of the D numbers
per tool (DRAM))
This allows you to customize the number of cutting edges to be configured for each tool to
the actual number of real cutting edges for monitoring purposes.
● It is also possible to rename D numbers in the NC and thus to allocate arbitrary D numbers
to the cutting edges.
Cutting edge number CE
When you rename D numbers, the information in the tool Catalog detailing the numbers defined
for these cutting edges is lost. It is, therefore, impossible to determine, following renaming,
which cutting edge of the Catalog is being referenced.
Since this information is required for retooling procedures, a cutting edge number CE has been
introduced for each cutting edge. This number remains stored when the D number is renamed.
The D number identifies the cutting edge compensation in the part program. This compensation
number D is administered separately from the cutting edge number CE (the number in the tool
Catalog). Any number can be used. The number is used to identify a compensation in the part
program and on the display.
The CE number identifies the actual physical cutting edge during retooling. The cutting edge
number CE is not evaluated by the NC on compensation selection during a tool change (only
available via the OPI).
The cutting edge number CE is defined with system variable $TC_DPCE[t,d]:
● t stands for the internal T number
● d stands for the D number.
Write accesses are monitored for collisions, i.e. all cutting edge numbers of a tool must be
different. The variable $TC_DPCE is a component of the cutting edge parameter data set
$TC_DP1 to $TC_DP25.
It is only practical to parameterize $TC_DPCE if the maximum cutting edge number (MD18105)
is greater than the maximum number of cutting edges per tool (MD18106).
In this case, the default cutting edge number is the same as the classification number of the
cutting edge. Compensations of a tool are created starting at number 1 and are incremented up
to the maximum number of cutting edges per tool (MD18106).
The cutting edge number CE is the same as the D number (in compatibility with the behavior
till now) if:
MD18105 ≤ MD18106.
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Function Manual, 06/2019, A5E47435126B AA
Tools