Instruction Manual PSx3xxEIP
32
A positioning to the upper end limit (Par. 36) with a loop length > 0 is not
possible, since the drive would have to cross the end limit for this. The same
applies to the lower end limit (Par. 38) with a loop length < 0.
3.2. Positioning sequence without loop
The mode “positioning without loop” mode is used primarily for moving the small
distances involved in fine adjustments. In this case, each position is approached
directly. This does NOT eliminate any play present in the spindle in question. The
PSx3xx internal gear backlash does not play a role in this case, as position data are
acquired directly at the output shaft.
4. Specials
4.1. Speed, acceleration and deceleration
Manual runs are performed at the maximum speed specified in Par. 58; positioning
runs are performed at the maximum speed specified in Par. 52. For all runs the
maximum acceleration in Par. 62 and the maximum deceleration in Par. 64 apply. At
the end of each run the maximum deceleration decreases during the approach to the
destination successively in order to realize a harmonic transient behaviour.
A stop command causes the drive to brake with the maximum deceleration,
independently of the setting in Par. 64.
4.2. Maximum starting torque and maximum torque
Via Par. 66 the maximum starting torque can be set, via Par. 68 the maximum driving
torque.
The starting torque is active for the period in Par. 76 after each start of travel. It
should always be slightly higher than the driving torque, since the drive requires more
torque for the acceleration phase than for constant driving.
Both values are not sharp torque limits, instead the motor current is limited to a value
which corresponds to the current consumption at the nominal speed at the set torque.
If a lower speed than the rated speed is set, the achievable torque is slightly higher
than at the (default) nominal speed.
If small torque limits are to be used, it must be considered not to use these
in combination with high speed values, as this can lead to unstable driving
behaviour
!
4.3. Response of drive in case of block
If during a run due to load the speed falls below the threshold parameter of 30% of
the selected maximum speed (Par. 74) for longer than 200 msec (Par. 60), the device
detects blockin
g, aborts the run and sets the “positioning error” bit (here the default
values are given). The drive from now on stands with the selected holding torque
(Par. 72).
New run commands can then be transmitted with no further steps to take, i.e.
transmitting a target value (change of the target value in the process data) starts a
new run.
An exception is (in case the drive is controlled with the help of process data), if the
run should go to the same target than before. In this case, deassert the release (bit 4
