Compensation Tables
06/2005
Danaher Motion
138 Rev
E
M-SS-005-03l
The values in the “source” columns are in absolute units, while the “target”
values are in relative units (i.e., the value specified in the table is added to
the current position of the axis, whether it is a geared, cammed or a regular
axis). A value different from 0 at the beginning of the table causes a jump at
the target axes whenever the source axes get to the minimum value
specified in the table.
The difference between the corrected position (
COMPPCMD
)
and the actual
position feedback determines the position error of the target axes.
PCMD
returns the position of the generator before correction.
The source
PFB
(for example, source1.pcmd=1, source2.pcmd=3.2,
source3.pcmd=4.5) is searched in the table and linearly transformed from the
previous points in the table to give the correction for the target positions.
While the source axis continues its movement along the specified zone, the
target axes change their positions according to the table. When one of the
sources goes beyond the max value there are no more correction added for
any of the axes in the table (correction=0). A jump may occur.
Correction values are assumed very small and will not cause a large jump in
the target axis.
VOSPD
and
PEMAX
are affected by the corrected position.
Change these values accordingly to avoid exceeding the maximum values.
While the compensation table is active, the values of the table cannot be
changed. After the table is created, only the “target” values can be change.
7.1.2. Access
Data
The compensation table data is arranged in the form of following target data
for the points for each individual axis. If there are three axes (A1, A3, A3),
there are three (
N
1,
N
2,
N
3) compensation points defined. To calculate the
index to access the table with the indexes i, j, k for A1,A2,A3, use:
index = i + j*N1 + k*N1*N2 .
7.1.3. Define
The compensation table is defined as a global variable.
Common shared comp1 as comp
CreateComp Comp1 3 ,4, 8
‘Creates a table with 3*4*8 number of rows and
'6 number of columns – 3 for the source & 3 for the target.
CompSet Comp1 A1 ,A3, A4 on A2, A6, A5
‘Sources A1 A3 A4 and targets A2 A6 A5 respectively.
The maximum and minimum positions of the table are set for every axis in
the compensation table as well as a multiplier:
Comp1.minposition[2] = 1.32
Comp1.maxposition[2] = 4.5
' Set the maximum value for the second axis in the table