Siemens SINUMERIK 840DE sl Function Manual page 283

The name ($NT_NAME (Page 279)) of the element of the kinematic subchain that is currently
active, which defines the starting point of the subchain for the tool reference point, must be
entered in the system variable $NT_T_CHAIN_FIRST_ELEM.
Note
Pure tool kinematics
The first element only has to be defined in $NT_P_CHAIN_FIRST_ELEM in special
circumstances; otherwise the system variable can remain empty. In this case, the ROOT
element is used as the first element.
Syntax
$NT_T_CHAIN_FIRST_ELEM[<n>] = "<ElementName>"
Meaning
$NT_T_CHAIN_FIRST_ELE
M:
<n>:
<ElementName>:
Example
For the first transformation, the name of the element of the kinematic subchain that defines the
starting point of the subchain for the workpiece reference point is "Baseoffset_2":
Program code
N100 $NT_T_CHAIN_FIRST_ELEM[1] = "Base-
offset_2"
Transformations
Function Manual, 06/2019, A5E47435470B AA
K12 transformation definitions with kinematic chains
Name of the element that defines the starting point of the currently ac‐
tive kinematic chain for the tool reference point.
Data type: STRING
Default value: ""
Range of val‐ Element names of the currently active kinematic chain
ues:
System variable or transformation index
Data type: INT
Range of val‐ 1, 2, ... (MD18866 $MN_MM_NUM_KIN_TRAFOS - 1)
ues:
Name of an element of the currently active kinematic chain
Data type: STRING
Comment
; 1st transformation,
; first element for the tool reference
point
4.2 Commissioning
283