Instruction Manual PSx3xxMod
24
b) Response of drive in case of block or manual displacement
If during a run due to load the speed falls below the threshold parameter of 30% (HR
70) of the selected maximum speed for longer than 200 msec (HR 83), the device
detects blockin
g, aborts the run and sets the ‘positioning error’ bit (here the default
values are given).
New run commands can then be transmitted with no further steps to take. An
exception is, if the run should go to the same target than before. In this case,
deassert the release (bit 4 of the control word) and assert it again, then transfer the
target position one more time.
If the PSx3xxMod is displaced by external force during standstill opposite to the loop
direction and the release bit (bit 4) as well as the release readjustment bit (bit 10) in
the control word are being set, the device will attempt to reach the previously
transmitted target value once again (readjustment). The device does not attempt to
readjust if rotated in the loop
direction; it merely sets the ‘manual rotation’ bit. If bit 6
(„run without loop“) is being set, the drive readjusts the position in both directions.
Deasserting the release and/or the release readjustment bit can completely stop the
readjustment process.
If at standstill the drive continuously looses its position, the attempt to
readjust starts exactly when the actual position is leaving the positioning
window (assumed that all the conditions above are being fulfilled). If the
motor power is missing at the time when this transition happens, the
readjustment fails and b
its10 (‘positioning error’) and 13 (‘motor power was
missing
’) will become active. If later the motor power comes back again,
there will be
no
further attempt to readjust. This is to prevent a situation
that suddenly a drive begins to run if motor power is being switched on.
c) Calculating the absolute physical position
The PSx3xxMod actuator includes an absolute measuring system with measurement
range of 250 rotations. This allows the user to determine the direction of rotation for
any desired portion of these 250 rotations.
The mapping of the desired positioning range to the physical positioning range is
done with the help of the parameter ‘upper mapping end’ (HR 50/51).
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.
For the realization of any desired positioning range independent of the possible
positioning range which is defined by the mounting situation (physical positioning
range) there are the following two possibilities:
1) Move the axle (for example a spindle) to the desired position, then move the drive
(with opened collar) to the position value which belongs to the physical position of
the axle, only then close the collar.
Examples:
a) Move the axle in middle position, then move the drive at no-load (with opened
collar) also to middle position (position 51200), then close the collar. The drive
is now capable of moving 125 rotations (±50000 increments by default) in each
direction.
