Singular Positions And Handling - Siemens SINUMERIK 840D sl Function Manual

F2: Multi-axis transformations
2.2 5-axis transformation
Alarm 17630 or 17620 is output for G74 and G75 if a transformation is active and the axes to
be traversed are involved in the transformation. This applies irrespective of orientation
programming.
If the start and end vectors are inverse parallel when ORIWKS is active, then no unique plane
is defined for the orientation programming, resulting in the output of alarm 14120.
If a transformation switch (switch On, switch Off or change transformation) is undertaken, alarm
14400 will be generated.
In the reverse situation, i.e. a tool radius offset is selected or deselected when a transformation
is active, no alarm message is output.
Multiple input of tool orientation
According to DIN 66025, only one tool orientation may be programmed in a block, e.g. with
direction vectors:
N50
If tool orientation is entered multiply, i.e. with direction vectors and with Euler angles, error
message 12240 "Channel X block Y tool orientation xx defined more than once" is displayed
and the NC part program stops.
N60
Tool orientation using orientation vectors
Polynomials can also be programmed for the modification of the orientation vector.
This method produces an extremely smooth change in speed and acceleration at the block
changes for rotary axes when the tool orientation has to be programmed over several blocks.
The interpolation of orientation vectors can be programmed with polynomials up to the 5th
degree. Polynomial interpolation of orientation vectors is described in the "Polynomial
Interpolation of Orientation Vectors" section.
Note
Further explanations of tool orientation using orientation vectors and their handling in machines
are given in:
Reference:
Function Manual, Basic Machine; Tool Offset; Orientable Toolholders (W1)
2.2.5

Singular positions and handling

Extreme velocity increase
If the path runs in close vicinity to a pole (singularity), one or several axes may traverse at a
very high velocity.
50
A3=1 B3=1 C3=1
A3=1 B3=1 C3=1 A2=0 B2=1 C2=3
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions