Siemens SINUMERIK 840D sl Function Manual page 914

S3: Synchronous spindle
14.4 Special features of synchronous mode
Even if a differential speed has been programmed, the following spindle remains under
position control if this is required by the coupling.
Note
The axial VDI interface signal NCK → PLC IS "Superimposed motion" is set (DB31, ...
DBX98.4) when setpoints in addition to the coupling setpoints are created by differential
speed programming.
Actual direction of rotation CW (DB31, ... DBX83.7)
The IS "Actual direction of rotation CW" (DB31, ... DBX83.7) refers to the resultant direction
of motor rotation.
IS PLC to NCK
Influence on following spindle via PLC interface
The effect of the axial VDI interface signals on the following spindle with differential speed in
speed control mode is described below.
Delete distance to go/Spindle Reset (DB31, ... DBX2.2)
The programmed differential speed and direction of rotation can be terminated by IS "Delete
distance-to-go/Spindle Reset" (DB31, ... DBX2.2). To delete the programmed speed only, it
is possible to set IS "Delete S value" (DB31, ... DBX16.7).
Resynchronize spindle 1/2 (DB31, ... DBX16.4 and 16.5)
The IS "Resynchronize spindle 1/2" (DB31, ... DBX16.4/16.5) are not locked. Any positional
offset is not compensated automatically by the coupling.
Invert M3/M4 (DB31, ... DBX17.6)
The IS "Invert M3/M4" (DB31, ... DBX17.6) only inverts the speed component additionally
programmed for the following spindle.
The motion component generated by the synchronous spindle coupling remains unaffected.
Spindle override (DB31, ... DBB19)
The "Spindle override" VDI interface (DB31, ... DBB19) only impacts on the speed
component additionally programmed for the following spindle. If the spindle override switch is
transferred to all axial inputs, then any change in the spindle override value is applied doubly
to the following spindle:
● once indirectly by a change in speed for the leading spindle and
● once in the programmed component of the following spindle.
The offset value can be adjusted accordingly in the PLC program.
914
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions