powerSTEP01
Functional description
Figure 10. Positioning command examples
Forward
direction
0
0
Present
position
Present
position
Target
Target
position
position
-221 +221-1
GoTo(Target pos)
-221 +221-1
GoTo_DIR(Target pos,FW)
AM12857v1
7.7.3
Motion commands
Motion commands produce a motion in order to perform a user-defined number of
microsteps in a user-defined direction that are sent to the device together with the command
(see Figure 11).
Performed motor motion is compliant to programmed speed profile boundaries
(acceleration, deceleration, minimum and maximum speed).
Note that with some speed profiles or motion commands, the deceleration phase can start
before the maximum speed is reached.
Figure 11. Motion command examples
SPEED
SPEED
programmed number of microsteps
programmed number of microsteps
programmed
maximum
speed
programmed
maximum
speed
Note: with some
acceleration/decelaration profiles
the programmed maximum speed
is never reached
programmed
ACCELERATION
programmed
DECELERATION
programmed
ACCELERATION
programmed
DECELERATION
programmed
minimum
speed
programmed
minimum
speed
time
time
AM15163v1
7.7.4
Stop commands
A stop command forces the motor to stop. Stop commands can be sent anytime.
The SoftStop command causes the motor to decelerate with a programmed deceleration
value until MIN_SPEED value is reached and then stops the motor keeping the rotor
position (a holding torque is applied).
The HardStop command stops the motor instantly, ignoring deceleration constraints and
keeping the rotor position (a holding torque is applied).
DocID025022 Rev 1
27/90
STMICROELECTRONICS [ ST ]
