Siemens SINUMERIK 840D sl Function Manual page 586

TE1: Clearance control - 840D sl only
15.6 Programming
Functionality
The current closed-loop control gain for clearance control is produced by the active
characteristic specified via machine data:
● MD62510 $MC_CLC_SENSOR_VOLTAGE_TABLE1 (coordinate voltage of interpolation
points sensor characteristic 1)
● MD62511 $MC_CLC_SENSOR_VELO_TABLE1 (coordinate velocity of interpolation points
sensor characteristic 1)
or
● MD62512 $MC_CLC_SENSOR_VOLTAGE_TABLE2 (coordinate voltage of interpolation
points sensor characteristic 2)
● MD62513 $MC_CLC_SENSOR_VELO_TABLE2 (coordinate velocity of interpolation points
sensor characteristic 2)
CLC_GAIN can be used to multiply the closed-loop control gain of the characteristic by a
programmable factor.
NOTICE
Imprecise characteristic
Increasing the gain (CLC_GAIN > 1.0) may lead to oscillation in the controlled axes!
Instant of activation
The modified closed-loop control gain is effective in the part program block in which CLC_GAIN
has been programmed or, if this block does not contain any executable instructions, in the next
part program block with executable instructions.
Response to characteristic changeover
The programmed factor remains active even when the gain characteristic is changed over with
CLC_SEL, i.e. it is immediately applied to the newly selected characteristic.
Response to CLC_GAIN=0.0
If the closed-loop control gain for clearance control is deactivated with CLC_GAIN=0.0, the
CLC position offset present at the time of deactivation is retained and is not changed. This can
be used for example when laser-cutting sheet steel to "skip over" sections of sheet that are
not to be machined without foundering.
If the tool orientation is changed when 3D clearance control is active and the closed-loop
control gain has been deactivated (CLC_GAIN=0.0), the CLC offset vector is rotated
simultaneously. This generally induces an offset in the CLC operating point on the workpiece
surface (see following diagram).
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Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions