Siemens SINUMERIK 828D Commissioning Manual page 46

Introduction and use of data classes
2.1 Data classes in the NC
Data class attribute
The data class attribute is set implicitly. The default setting of the data class attribute can be
explicitly changed.
● In general, data from the active file system is assigned to a data class as it belongs to a
certain file.
Example: Compensation data (data from CEC, EEC or QEC) is assigned to the "Individual"
data class. If data is generated as a result of a definition (GUDs and macros) then this data
also inherits the data class in which the definition file is located. GUD from UGUD.DEF are
assigned the "User" data class.
● However, if the data definition and data content are in different data classes , then this must
be specified in the data definition.
Example: The definition of the GUD, which defines a probe, should be located in the
"Manufacturer" data class, as it is required to run the manufacturer cycles.
However, the value of the data should belong to the "Individual" data class as the probe
type can differ from machine to machine. This is the reason why the additional variable
attribute "DC" (DataClass) has been introduced:
MGUD.DEF ("Manufacturer" data class)
DEF CHAN DCI INT CALIPER
The definition of the data class of the data content can only be "less than or equal to" the data
class of the definition. Any other configurations are rejected with an alarm.
For this purpose, the following weighting of the data classes is assumed: M > I > U
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Commissioning Manual, 10/2015, 6FC5397-3DP40-5BA3
CNC commissioning