Danfoss MCO 305 Design Manual page 225

MCO 305 Design Guide
The Offset Filter Time defines the time which
should be used to compensate one marker
distance.
Starting with MCO 5.00 not only the offset over the
given time is distributed, but also a trapezoidal
movement is calculated which is superimposed
onto the normal synchronizing movement.
This is used to calculate limiting accelerations and
velocity with the assumption that normally 20 %
for acceleration, 60 % with constant velocity, and
another 20 % of the time to decelerate will be
used. Based on that interpretation, it is calculated
what acceleration and deceleration ramps should
be used and how the maximum velocity needs to
be limited to reach that.
This new distribution is not only used for offsets,
but also for start corrections (first marker correc-
tion), normal marker corrections and accumulated
errors caused by REVERS setting.
33-28 Marker Filter Configuration
SYNCMFPAR
Option
Normal SYNCMFTIME filter function
Constant value for the Marker Filter
No correction of SYNCFACT
Time constant based on Filter Time
for Marker Correction SYNCMFTIME
Only smoothing of the correction
value, time constant as [4]
Execute always marker distance
averaging.
Function
SYNCMFPAR is used to influence the behavior of
marker filtering, see par. 33-29 Filter Time for
Marker Correction.
The following values are bit valences and can be
combined with each other:
0 = Normal filter function, see par. 33-29 Filter
Time for Marker Correction SYNCMFTIME.
1 = Instead of the dynamic marker filter constant
a constant value of
SYNCMFTIME / 300 is used.
2 = Gear correction is not executed.
default setting
__ Parameter Reference __
[0]
[1]
[2]
[4]
[16]
[64]
[ ] value for use in communication via serial communication port
®
MG.33.L5.02 – VLT is a registered Danfoss trademark
4 = The Filter Time for Marker Correction (par.
33-29) is used instead of the Offset Filter
Time (par. 33-27) to calculate the time
constant for the correction value filter
(G_Korrektur)
16 = Instead of calculation of the filtered marker
distance and deviation, only the correction
value is smoothed by a PT filter. Time
constant for that filter on bit valence 4 basis
(see above).
64 = Marker averaging and marker check are also
executed when SYNCM is inactive.
If par. 33-29 SYNCMFTIME is set, then the
G_MMarkerDist is calculated a little differently. If
the time set results in a number of markers which
is smaller than 100, then at least 100 are taken to
calculate the average marker distance (Filter). This
only affects the calculation of the marker distance.
The other filter calculations (deviation) are still
done with the number of markers calculated by par.
33-29 SYNCMFTIME and actual velocity of master.
See also Marker Correction illustration in chapter
"Technical Reference".
33-29 Filter Time for Marker Correction
SYNCMFTIME
Range [Unit]
0 – MLONG [ms]
0 = Off;
if par. 33-26 Velocity Filter is negative,
the marker correction is spread by
SYNCVFTIME /100
Application Example
Newspaper manufacturing needed this sort of filte-
ring to synchronizing a chain to the newspaper
stream coming from a printing machine. Because
the newspaper stream is not quite constant, the
problem is that if synchronized without filter the
movements of the chain are very hard and dyna-
mic. With all other sort of filters the system starts
swinging in sinusoidal waves.
When using this complex filter the synchronizing
works very well and solves the problem.
Function
SYNCMFTIME is given in ms and is used as follows:
0
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