Siemens SINUMERIK 840DE Programming Manual page 267

Requirements
The spindle must be capable of operation in position-control mode.
Position with SPOSA=, SPOSA[n]=
The block step enable or program execution is not affected by SPOSA. The spindle
positioning can be performed during execution of subsequent NC blocks. The program
moves onto the next block if all the functions (except for spindle) programmed in the current
block have reached their block end criterion. The spindle positioning operation may be
programmed over several blocks (see WAITS).
Notice
If a command which implicitly causes a preprocessor stop is read in a subsequent block,
execution of this block is delayed until all positioning spindles are stationary.
Positioning with SPOS=, SPOS[n]= and positioning with M19=, M19[n]=
The block step enabling condition is fulfilled when all functions programmed in the block
have reached their block end criterion (e.g., all auxiliary functions acknowledged by the PLC,
all axes have reached end point) and the spindle has reached the programmed position.
Speed of the movements
The speed or delay response for positioning is stored in the machine data and can be
programmed.
Specify spindle position
As the commands G90/G91 have no effect here, the corresponding units of measurements
such as AC, IC, ACN, ACP explicitly apply. If nothing is specified, traversing automatically
takes place as for DC.
End of positioning
Programmable by means of the following commands: FINEA [Sn], COARSEA [Sn],
IPOENDA [Sn].
Settable block change time
For single axis interpolation mode, a new end of motion can be set in addition to the existing
end of motion criteria based on FINEA, COARSEA, IPOENDA.The new criterion can be set
within the braking ramp (100-0%) using IPOBRKA.
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
7.4 Positioning spindles (position-controlled axis operation) (SPOS, M19 and SPOSA)
Feedrate Control and Spindle Motion
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