Velocities - Siemens SINUMERIK 840D sl Commissioning Manual

10.2.10

Velocities

Max. axis velocity or spindle speed
The maximum possible axis velocities and spindle speeds depend on the machine design,
drive dynamics and the encoder limit frequency of the individual drives.
Max. progr. tool path velocity
The maximum programmable tool path velocity results from the maximum axis velocities of
the axes involved in the path programmed.
Max. tool path velocity
The maximum tool path velocity at which traversing is possible within a parts program block
results as follows:
Upper limit
To guarantee that parts program blocks are executed continuously (control margin), the NC
limits the tool path velocity within a parts program block to 90% of the max. possible tool
path velocity as follows:
For example, in the case of parts programs generated by means of CAD system, which
contain extremely short blocks, this limiting of the path velocity can result in a strong
reduction of the path velocity over several parts program blocks.
The function "Online compressor" can help to avoid such sudden velocity dips.
Literature
Programming Manual Work Preparation: Compressor COMPON/COMPCURVE
IBN CNC: NCK, PLC, drive
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
NCK start-up
10.2 System data
119