Siemens SINUMERIK 840D sl Function Manual page 1346

V1: Feedrates
17.4 Feedrate control
Note
POS instead of POSA
If feedrates, sparking out time (dwell time) or return path are programmed for an axis on
account of an external input, this axis must not be programmed as POSA axis (positioning axis
over multiple blocks) in this block.
Note
Status query
It is also possible to poll the status of an input for synchronous commands of various axes.
Note
LookAhead
Look Ahead is also active for multiple feedrates in one block. In this way, the current feedrate
can be restricted by the Look Ahead value.
Application
The "Multiple feedrate values in one block" function is used primarily for grinding, but is not
restricted to it.
Typical applications are, for example:
● Analog or digital calipers
Depending on whether the external inputs are analog or digital, various feedrate values, a
dwell time and a retraction path can be activated. The limit values are defined via the setting
data.
● Switching from infeed to working feedrate via proximity switch
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Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions