Siemens SINUMERIK 840D sl Function Manual page 1021

negatively by InPos="1" or Error = "1". The output parameters are deleted when the relevant
trigger signal is reset and the function has been completed.
To be able to control an axis or spindle via the PLC, it must be activated for the PLC. This can,
for example, be achieved by calling the block with activation of the "Start" or "Stop" parameter.
When you do this, the block requests control of the spindle/axis from the NC.
The NC signals the status of the spindle/axis in the associated axis-specific interface DB31, ...
DBX68.4 - 7. Once the axis/spindle is operating under PLC control, the travel command for
the active status can be evaluated via the relevant axis-specific interface.
Upon completion ("InPos" is True, "Start" changes to zero), the axis/spindle check function is
switched to a neutral status using block FC18.
Alternatively, the PLC user program can also request control for the PLC before calling FC18.
By calling this function several times in succession, a better response by the spindle/axis can
be obtained as the changeover process in the FC can be omitted.
Activation through the PLC user program is executed in the corresponding spindle interface
in byte 8.
After return of the check, the spindle can again be programmed by the NC program.
References
● Function Manual, Basic Functions; Spindles (S1)
● Function Manual, Extended Functions; Positioning Axes (P2)
● Function Manual Expanded Functions; Indexing Axes (T1)
Changed response behavior of the axis/spindle
If several block calls (FC18) have been programmed for the same axis/spindle in the PLC
user program, then the functions concerned must be interlocked by conditional calls in the
user program. The conditional call of a started block (parameter Start or Stop = TRUE) must
be called cyclically until the signal state of output parameter "Active" or "InPos" changes from
1 to 0.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
WARNING
P3: Basic PLC program for SINUMERIK 840D sl
13.17 Block descriptions
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