Siemens SINUMERIK 840Di sl Programming Manual page 546

Glossary
System variables
A variable that exists without any input from the programmer of a → part program. It is
defined by a data type and the variable name preceded by the character $. See → User-
defined variable.
TappingRigid
This function allows threads to be tapped without a compensating chuck. By using the
method whereby the spindle, as a rotary axis, and the drilling axis interpolate, threads can be
cut to a precise final drilling depth (e.g. for blind hole threads) (requirement: spindles in axis
operation).
Text editor
See → Editor
TOA area
The TOA area includes all tool and magazine data. By default, this area coincides with the
→ channel area with regard to the reach of the data. However, machine data can be used to
specify that multiple channels share one → TOA unit, so that common tool management data
is then available to these channels.
TOA unit
Each → TOA area can have more than one TOA unit. The number of possible TOA units is
limited by the maximum number of active → channels. A TOA unit includes exactly one tool
data block and one magazine data block. In addition, a TOA unit can also contain a
toolholder data block (optional).
Tool
Active part on the machine tool that implements machining (e.g., turning tool, milling tool,
drill, LASER beam, etc.).
Tool nose radius compensation
Contour programming assumes that the tool is pointed. Because this is not actually the case
in practice, the curvature radius of the tool used must be communicated to the control which
then takes it into account. The curvature center is maintained equidistantly around the
contour, offset by the curvature radius.
Tool offset
Consideration of the tool dimensions in calculating the path.
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Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals