Siemens SINUMERIK 840D sl Programming Manual page 120

Fundamentals
2.7 Feed control
Note
With incremental dimensions IC(<value>), spindle positioning can take place over several
revolutions.
Note
If position control was activated with SPCON prior to SPOS, this remains active until SPCOF
is issued.
Note
The control detects the transition to axis mode automatically from the program sequence.
Explicit programming of M70 in the part program is, therefore, essentially no longer necessary.
However, M70 can continue to be programmed, e.g. to increase the legibility of the part
program.
Further information
Positioning with SPOSA
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).
Note
If a command, which implicitly causes a preprocessing stop, is read in a following block,
execution of this block is delayed until all positioning spindles are stationary.
Positioning with SPOS/M19
The block step enabling condition is met when all functions programmed in the block reach their
end-of-block criterion (e.g. all auxiliary functions acknowledged by the PLC, all axes at their end
point) and the spindle reaches the programmed position.
Velocity of the movements:
The velocity and the delay response for positioning are stored in the machine data. The
configured values can be modified by programming or by synchronized actions, see:
● Feedrate for positioning axes / spindles (FA, FPR, FPRAON, FPRAOF) (Page 122)
● Programmable acceleration compensation (ACC) (Page 125)
Specification of spindle positions:
As the G90/G91 commands are not effective here, the corresponding dimensions apply
explicitly, e.g. AC, IC, DC, ACN, ACP. If no specifications are made, traversing automatically
takes place as for DC.
Synchronize spindle movements with WAITS
120
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming