Siemens SINUMERIK 840C - Manual (Page 907)

12 Functional Descriptions 12.93
12.18.4 Link types with constant link factor
12.18.4 Link types with constant link factor
12.18.4.1 Setpoint link
When position-controlled leading drives are used, the command variable for the following drive
can be derived from the part setpoints of the leading drives, thus ensuring a better response to
dynamic control processes than can be achieved with an actual value link. The setpoint-
position link is the most effective when the leading and following drives have been well co-
ordinated. The quality of synchronism can be improved still further when the compensatory
controller is activated.
Since the part setpoints for the leading and following drives are input simultaneously,
synchronism during acceleration and braking can also be assured provided that the leading
and following drives are set to have the same dynamic response (identical rise time, servo gain
factor, setpoint filter, etc.). For this reason, the setpoint link should be used only for leading
and following drives of the same type (leading axis -> following axis or leading spindle ->
following spindle) since the dynamic performance of the drives is comparable only in such
cases.
Leading/following drives in a setpoint link with compensatory controller and following drive overlay
Following drives
Leading drive 1
k
LD
2
LD
3
k
FD
ov
LD
5
LD
4
LD
1
Inter-
polator
Setpoint
conditio-
ning
Following
drives
Position
controller
Position
controller
Compensa-
tory control
M
Feedfor-
ward
control
Feedfor-
ward
control
M
LD
4
LD
5
FD
ov
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SINUMERIK 840C (IA)