Danfoss VLT5000 SyncPos Operating Instructions Manual page 188

33 DFLTVEL
DFLTVEL indicates the default velocity which is
always used when no velocity is defined in the pro-
cess set. This value refers to the Velocity resolu-
tion tion
tion tion tion VELRES (22).
Content
Default velocity
Parameter Group
Axis parameter Velocity AXV
CAM-Editor: index card Velocity
Unit
1
/
VELRES;
1
Standard = / = %
100
Value range
1 ... VELRES
34 DFLTACC
DFLTACC indicates the acceleration used when no
explicit statements have been made. This statement
is made in relation to RAMPMIN (31) and refers to
the VELRES (22) parameter.
Content
Default acceleration
Parameter Group
Axis parameter Velocity AXV
CAM-Editor: index card Velocity
Unit
1 /
VELRES;
Standard = 1 / = %
100
Value range
1 ... VELRES
MG.10.J8.02 – VLT is a registered Danfoss trade mark
Programmable SyncPos motion controller
35
You can limit the bandwidth in which the PID con-
troller should function, for example to avoid the
Velocity resolu- Velocity resolu-
Velocity resolu- Velocity resolu- built-up of a vibration if you are operating a system
which could be jeopardized by vibrations.
However, then it is necessary to enter considerably
higher values for the parameters FFVEL (36) and
FFACC (37) in order to achieve the corresponding
control. A system adjusted in such a manner is not
as dynamic as it could be, but is considerably
more stable and tends to experience less uncon-
trolled vibrations.
Content
Bandwidth within which the PID filter is active
Parameter Group
Axis parameter PID-Controller AXR
★ 50
CAM-Editor: index card PID
Unit
%
The value 1000 means that the PID filter can out-
put the full command value. For a BANDWIDTH of
500 only 50 % of the set value is output. Thus,
values less than 1000 limit the P-share accordingly.
Value range
0 ... 1000
3 6
When a control has a limited bandwidth then a
base velocity must be set so that it can be ruled out
that the control will entirely prevent the drive from
running due to the limit set. FFVEL indicates the
value with which the velocity feed-forward is
completed.
When working with a normal PID algorithm the
★ 50
FFVEL must always be the same as the KDER factor
in order to achieve typical dampening.
Content
Velocity feed-forward
Parameter Group
PID-Controller
Unit
%
Value range
0 ... 65000
BANDWIDTH (706)
FFVEL (707)
★ 1000
★ 0
187