Siemens SINUMERIK 840C - Manual (Page 935)

12 Functional Descriptions 10.94
12.18.13 Start-up
• If the drives involved have varying dynamic response characteristics (and if it is not
meaningful to match them by setting the same response values), then you can use a
setpoint filter for the purpose of matching. You can activate the setpoint filter for axes with
NC MD 1820*, bit 0; you must enter the setpoint filter time constant in NC MD 1272* or
486*.
Note:
Please note "Parameter set switchover" function description with SW 4 and higher.
• If the individual drives deviate too much in terms of dynamic response (e.g. following axis
and leading spindle) and if a setpoint filter does not produce satisfactory results, then you
must select the actual value link as the link structure.
The dynamic response of axes which interpolate with leading and
following axes must likewise be matched to the other axes involved.
Instructions for setting with feedforward control
• Set individual axes with servo gain factor, feedforward control factor and symmetrizing time
constant such as to obtain a good response to disturbances and setpoint changes.
• Calculate substitute time constants of the individual axes according to the formula:
1–V
T
SUBS
= ––––– + T
SYM
K
v
V: Feedforward control factor
T
SYM
: Symmetrizing time constant
• Make fine adjustment by changing the setpoint filter time constant when all axes/spindles
are traversing at constant speed until the following error on all axes/spindles is the same.
• Set the axial setpoint filter (NC MD 1272* or 486*) by entering the difference between the
time constants of this axis/spindle and the slowest axis/spindle in the grouping.
Kvx= value (NC MD 252*, 1320* or 435*ff) * 100
Vx= value (NC MD 312*,1260* or 465*) * 1000
T
SYM
1
= value (NC MD 392*, 1324* or 467*) * 10
12–160 © Siemens AG 1992 All Rights Reserved 6FC5197- AA50
SINUMERIK 840C (IA)