Nk_Off_Dir, $Nk_Axis, $Nk_A_Off (Parameterization For $Nk_Type = Axis_Lin) - Siemens SINUMERIK 840D sl Function Manual

5.2.3.6

$NK_OFF_DIR, $NK_AXIS, $NK_A_OFF (parameterization for $NK_TYPE = AXIS_LIN)

$NK_OFF_DIR
Function
The direction vector along which the linear axis $NK_AXIS assigned to the element moves,
should be entered in the system variable. The output coordinate system therefore results from
the input coordinate system, offset by the current position value of the linear axis and the work
offset specified in $NK_A_OFF.
Supplementary conditions:
● The direction vector must be specified as an absolute value, i.e. in relation to the world
coordinate system.
● The direction vector must be specified so that it points in the positive traversing direction
of the machine axis.
● The absolute value of the direction vector must be greater than 1*10
Syntax
$NK_OFF_DIR[<n>,<k>] = <value>
Meaning
$NK_OFF_DIR:
<n>:
<k>:
<value>:
Example
; The linear axis of the 9th element moves along the direction vector. The direction vector is
the unit vector (1; 0; 0), rotated through α=90° in the X/Y plane and β=10° in the Y/Z plane, in
relation to the world coordinate system. The following values result from this for the individual
components of the direction vector:
● X component = cos(α) * cos(β) = cos(90) * cos(10) = 0.0
● Y component = sin(α) * cos(β) = sin(90) * cos(10) ≈ 0.985
● Z component = sin(β) = sin(10) ≈ 0.174
Special functions
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Direction vector (X; Y; Z)
Data type: REAL
Range of values: Direction vector: 1*10
Default value: (0.0, 0.0, 0.0)
System variable or element index
Data type: INT
Range of values: 0, 1, 2, ... ($MN_MM_MAXNUM_KIN_CHAIN_ELEM - 1)
Coordinate index
Data type: INT
Range of values: 0 → X; 1 → Y: 2 → Z
Coordinate value
Data type: REAL
Range of values: - max. REAL value ≤ x ≤ + max. REAL value
K7: Kinematic chain - only 840D sl
5.2 Commissioning
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-6
< |vector| ≤ max. REAL value
-6
195