SIXpack 2 – Manual (V1.10 / January 29
th
, 2010)
32
6.6
Commands for axis movements
The SIXpack 2 provides different possibilities to move the axis. Which one to choose is related to the demands of
the application.
Basically there is the possibility to move the motor on the axis from a to b (ramps run) or with a fixed velocity
(rotation) until the next velocity command.
6.6.1
Basic ramp run
The ramp run requires the configuration of a reference run with the values for
Poslimit
, acceleration and
velocity (see CMD $15).
Through the command
StartRamp
, CMD $23 every position, defined by
Poslimit
can be achieved. The target is
defined by the variable
TargetPosition
(CMD $24, SQPack-tab “PI Controller”). The motor is decelerated before
it reaches the target position to stop at the exact target.
Figure 6.5: Schema of ramp generation
6.6.2
Start of constant rotation
For a rotation with a constant velocity the command
ConstantRotation
(CMD $25) transmits the variable
Velocity
which defines the velocity for the constant move (calculation in 6.3).
After receiving the command the motor is accelerated with the maximum acceleration
AMax
until the speed
defined in
Velocity
is reached. To stop the axis the command
ConstantRotation
is used again and
Velocity
is
set to 0.
6.6.3
Change target position for ramp run
To change the target position of an active ramp run use the command
SetTargetPosition
(CMD $24, SQPack-tab “PI
Controller”) to transmit the variable
TargetPosition
with the new target of the movement.
If the motor already reached its defined target
SetTargetPosition
takes no effect. To avoid failures and to be sure
the desired position is reached it is recommended to send the command
StartRamp
(CMD $23) with the actual
target position in addition afterwards. If the mode
ConstantRotation
(CMD $25) was active, before, the motor is
stopped and than moved to the target position.
6.6.4
Starting different motors synchronous
The command
StartRampParallel
(CMD $29) is used to start multiple ramp runs. Before this command is sent each
target position should be set with the command
SetTargetPosition
(CMD $24). When all motors are inactive the
parallel ramp run can be started.
Example:
In Figure 6.6 (left) a parallel started ramp run of Motor 1 and Motor 2 is demonstrated. The parameters
for velocity and acceleration (refer to 6.6.1) are identical for both motors but the distance for motor 1 is longer.
Both motors start at the same time, accelerate synchronous and have the same maximum velocity. Motor 2 reaches
its target position earlier and therefore finishes the ramp earlier than motor 1.
