6
6.2
Positioning mode (P0700 = 3, from SW 2.1)
6-378
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SIMODRIVE 611 universal Description of Functions (FBU) – 04.05 Edition
The position loop gain (Kv factor) defines which following error is obtai-
ned at which axis traversing velocity.
The mathematical (proportional) equation is as follows:
Kv factor=
Velocity v
Following error
s
[1000/min]
1 m
min
mm
=
1000
min
The K
v
factor influences the following important characteristic quantities
of the axis:
Positioning accuracy and holding control
Uniformity of the motion
Positioning time
The better the axis design (high degree of stiffness), then the higher is
the achievable K
v
factor, and therefore the better the axis parameters
from the technological perspective (lower following error).
Note
The stable position loop gain which can actually be set for the
complete position control loop is influenced by time constants as well
as backlash (play) and spring elements in the control loop.
The required Kv factor is entered in P0200:8.
The actual (measured) Kv factor is displayed in P0031.
Table 6-24
Parameters for the position loop gain
No.
Name
Min.
Stan-
dard
Max.
Units
Ef-
fec-
tive
0200:8
Kv factor (position loop gain)
0.0
1.0
300.0
1 000/min
Im-
medi-
ately
The Kv factor defines at which traversing velocity of the axis which following error is obtained.
Low Kv factor:
Slow response to setpoint–actual value difference
s is high
High Kv factor:
Fast response to setpoint–actual value difference,
s is small
Examples: Kv
factor
Significance
= 0.5
at v = 1 m/min an
s of 2 mm
= 1 is obtained
at v = 1 m/min an
s of 1 mm
= 2 is obtained
at v = 1 m/min an
s of 0.5 mm is obtained
Note:
The following parameters are available for position loop gain diagnostics:
P0029
Following error
P0030
System deviation, position controller input
P0031
Actual Kv factor (position loop gain)
Refer under the index entry ”Diagnostics of the motion status”
Position
loop gain
(Kv factor)
P0200:8
P0031
6 Description of the Functions
01.99
! not 611ue !
