Groups 06/2005
Danaher
Motion
122 Rev
E
M-SS-005-03l
Group acceleration is the orthogonal combination of the axes' acceleration.
Group acceleration and deceleration are limited according to the axes‘
values.You can impose limits to constrain the time during which group
acceleration and deceleration occurs.
<group>.TIMEACCELERATION
and
<group>.TIMEDECELERATION
define the duration of the acceleration
phase.
6. 4
P
OSITION
Group position differs from axis position in that a single property must
represent the position of multiple axes. In some cases, the individual axis
properties are maintained so that the property becomes a vector with two or
three entries. This is the case for
POSITIONFEEDBACK
or
POSITIONCOMMAND
. In other cases, the position from multiple axes are
combined using the square root of the sum of the squares, as for
POSITIONERRORMAX
.
6.4.1. Vector
With groups, three position properties are vectors: the position command,
position feedback, and position final. In each case, the quantities in the
vector are equivalent to the individual axis properties. For example, you can
set
POSITIONFINA
L as part of a
MOVE
:
Move MyGroup {5.5, 6.5}
This sets
PFINAL
of the first axis to 5.5 and the second to 6.5. Querying the
position feedback from a two-axis group from the terminal also returns a
vector. For example:
? MyGroup.PFb
returns:
(5.003, 6.003)
The positions in these vectors are ordered according to the way the group
was created with
Common…As Group
. The first axis declared occupies the
first position in the vector, the second occupies the second, etc.
6.4.2. Scalar
Other group position properties are scalar. These properties are the
orthogonal combination of the axis properties. These properties include:
POSITIONERROR
POSITIONERRORMAX
POSITIONERRORSETTLE
POSITIONTOGO
If MyGroup is formed with Axis1 and Axis2, and AXIS1.POSITIONTOGO = 1
and AXIS2.POSITIONTOGO=1, MYGROUP.POSITIONTOGO = 1.414, the
orthogonal combination of the two axes' POSITIONTOGO. Similarly, when
you set
POSITIONERRORMAX
or
POSITIONERRORSETTLE
, the position
error they are compared to is the orthogonal combination of the axes'
POSITIONERROR
.
