halstrup-walcher PS*3**PL series, Инструкция по эксплуатации

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Instruction Manual PSx3xxPL
24
Hence the PSx3xxPL differs between the following steps of a positioning sequence
(Presumption: the target position is always approached through backward motion, i.e.
the length of loop is > 0, which corresponds to the drawing above):
1. New position value is larger than the current value: The device overruns the target
position by 5/8 of one rotation, then approaches the exact position in backward
motion.
2. New position value is smaller than the current value: The position will be
approached directly.
3. New position value is smaller than the current value, but before there was a
forward run without loop (e.g. a manual run): Because the loop length is > 0, the
device by all means approaches the position by moving in backward direction.
The distance in backward direction is at least the length of loop. To achieve this,
the device first will run in forward direction, if necessary (i.e. in opposite to the
actually desired direction). The maximum length of this run is the length of loop.
Once the target position has been reached, the device compares it to the internal
absolute encoder status. If a discre
pancy is detected, the device then sets the “error”
bit (bit 9 in the status word).
In delivery state the length of loop is < 0, i.e. each target position is approached in
forward direction.
It is not possible to perform a positioning run to the upper limit (SDO #2016)
with a length of loop > 0 because the drive would have to run past the
upper limit in order to do so. The same applies to the lower limit (SDO
#2017) with a length of loop < 0.
e) Positioning sequence without loop
The
“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 PSx3xxPL
internal gear backlash does not play a role in this case, as position data are acquired
directly at the output shaft.
f) Calculating the absolute physical position
The PSx3xxPL actuator includes an absolute measuring system with measurement
range of 256 rotations. In order to avoid an overflow when the drive is switched off
and moved by an external force, the user can only command positionings in the range
of 250 rotations. Thus the upper as well as the lower 3 rotations of the measurement
range are inaccessible.
The mapping of the desired positioning range to the physical positioning range is
done with the help of the parameter ‘upper mapping end’ (SDO #2028).
In the delivery state, the drive is at position 51200, the upper limit switch is set to
101200 and the lower limit switch is set to 1200, yielding a positioning range of ±125
rotations (±50000 increments). So if the desired positioning range doesn’t exceed
±125 rotations, in delivery state none of the following actions to adjust the positioning
range have to be taken.