Rounding According To A Path Criterion (G641) - Siemens SINUMERIK 828D Function Manual

3.3.3.1

Rounding according to a path criterion (G641)

Function
In continuous-path mode with rounding according to a path criterion, the size of the rounding area is influenced
by the path criteria ADIS and ADISPOS.
The path criteria ADIS and ADISPOS describe the maximum distances which a rounding block can occupy
before and after a block.
Note
Acute angles produce rounding curves with a large degree of curvature and therefore cause
a corresponding reduction in velocity.
Note
ADISPOS is programmed in the same way as ADIS, but must be used specifically for
movements in rapid traverse mode G00.
Scope of the path criterion
• ADIS or ADISPOS must be programmed. If the default is "zero", G641 behaves like G64.
• If only one of the blocks involved is rapid traverse G0, the smaller rounding distance applies.
• If a very small value is used for ADIS, the control must make sure that every interpolated block, even an
intermediate rounding block, contains at least one interpolation point. The maximum path velocity is thereby
limited to ADIS / interpolation cycle.
• Irrespective of ADIS and ADISPOS, the rounding area is limited by the block length.
In blocks with short distances (distance < 4* ADIS and < 4 * ADISPOS respectively), the rounding distance is
reduced so that a traversable part of the original block is retained. The remaining length depends on the axis
path and is approximately 60% of the distance still to be traversed in the block. ADIS or ADISPOS is therefore
reduced to the remaining 40% of the distance to be traversed. This algorithm prevents a rounding block being
inserted for a very small change in contour. In this case, switchover to continuous­path mode G64 is
automatic until rounding blocks can be inserted again.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
B1: Continuous­path Mode, Exact Stop, LookAhead
3.3 Continuous-path mode
161