Description of the Software Modules and Parameters
Parameter manual
b maXX
BM3000
Document no.: 5.12001.07
397
4
Remarks:
m
Mode 0:
As a result of the linear extrapolation of speed and position, feedforward of the two val-
ues is achieved. The dead time between the input set value to the set value manager
and the set value to the controller input is consequently reduced. The procedure is only
recommended for very small changes in acceleration, since the extrapolation is no lon-
ger exact for each change in acceleration. This can lead to overshooting of the intend-
ed position and intended speed at the controller input.
m
Mode 1:
As a result of the linear interpolation of speed and position, Mode 1 avoids the negative
effect described under Mode 0 for changes in acceleration. A dead time is generated
about one set value manager cycle for the speed and about two cycles for the position
instead.
m
Mode 2:
This mode is a mixture of Modes 0 and 1. The position is linear extrapolated, the speed
linear interpolated. As a result of the interpolation of the speed, overshoots in the speed
set value or speed feedforward value are avoided. At the same time, due to the linear
extrapolation of the position the position controller receives a deadtime-optimized po-
sition set value.
m
Mode 3:
The mode 3 carries out a linear interpolation speed and a quadratic interpolation of the
position. As in mode 1 the position is delayed by two set value manager cycles and the
speed by one cycle.
m
Mode 4:
Mode 4 carries out a quadratic interpolation speed and a cubic interpolation of the po-
sition. Here the position and the speed is delayed by two set value manager cycles.
111.7
External speed feedforward
This parameter permits the presetting of an external speed feedforward by a fieldbus.
This parameter takes effect in operating mode Position control with synchronous set val-
ue specification (
= -4) only. The function is activated by
Controller op-
tions bit 3 = 1.
NOTE!
If several axes are to be operated collectively, the same interpolation mode should
be set on each axis.