Danfoss VLT 5000 Series Manual

VLT
®
5000 SyncPos option
MG.10.J4.02 – VLT is a registered Danfoss trade mark
136
14 TIMER
The TIMER parameter determines the sampling
time of the control algorithm.
For example, increase the value of the factory
settings
• for very low pulse frequency, such as from 1
to 2 qc per sampling time. You need at least
10 to 20 qc per sampling time.
• Or for very slow systems with a long dead
time. If 1 ms is used here for control, large
motors will vibrate.
Content
Sampling time for PID control
Parameter Group
AXR
Unit
msec
Value range
1… MLONG ★ 1
Accordingly, the value should not be set
higher than 1000 (= 1 s). This would be
a very slow control.
NB!
Note that is has a direct effect on the PID
loop e.g. if you double the TIMER the
KPROP (11) has twice the effect.
15 POSERR
The maximum
TT
TT
T
olerated position errorolerated position error
olerated position errorolerated position error
olerated position error POSERR
defines the tolerance allowed between the current
actual position and the calculated command posi-
tion. If the value defined with POSERR is excee-
ded then the position control is turned off and a
position error is triggered.
Content
Maximum
TT
TT
T
olerated position errorolerated position error
olerated position errorolerated position error
olerated position error
Parameter Group
AXR
Unit
qc
Value range
1 … MLONG ★ 20000
The maximum
TT
TT
T
olerated position error olerated position error
olerated position error olerated position error
olerated position error does not
affect the positioning accuracy, but merely deter-
mines how precisely the theoretically calculated
path of motion must be followed, without an error
being triggered.
NB!
For safety reasons the maximum
TT
TT
T
oleratedolerated
oleratedolerated
olerated
position errorposition error
position errorposition error
position error selected should not be too
large since this could be dangerous for both the
machine and its operator.
On the other hand, if the values for the
TT
TT
T
oleratedolerated
oleratedolerated
olerated
position errorposition error
position errorposition error
position error are too small this could result in
frequent errors. As a guideline, it is wise to set the
quadruple of Encoder counts per revolution. This
corresponds to one encoder rotation.
Parameter Reference

Danfoss VLT 5000 Series Specifications

General

Brand	Danfoss
Model	VLT 5000 Series
Category	DC Drives
Language	English