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The immersion point is lowered by P108 (maximum container height) during unlocking.
The immersion point thus behaves in the same way as the blocked regions (except that P72 is
not included in the process).
6.11
Collision protection - soft approach
6.11.1
Soft approach
Blocked regions are always taken into account in semi-automatic mode (SAM). This soft
approach function can be activated or deactivated in manual mode. Soft approach is activated
using the control bits MAN_FIXOBST_OFF = FALSE and/or MAN_VAROBST_OFF = FALSE
(STW_PLC_Common). These enable the fixed and/or variable blocked regions to be taken into
account.
Fixed blocked regions
The velocity is reduced to 0% before a fixed blocked region. Parameters P173/P174 Braking
distance reserve (trolley and hoist) and P172 Creep range (trolley only) can be used to shift the
braking point. If a creep range is defined for the trolley, the velocity is always 10% of maximum
velocity. As soon as the drive stops before the blocked region, the status bit
STOP_AT_OBST_MAN_TR or STOP_AT_OBST_MAN_HO is output.
The braking distance reserve is not a blocked region; it simply shifts the stopping point. When
the spreader is located within the braking distance reserve of the hoist, lowering is no longer
possible but the trolley can continue to move without restriction. The same applies to the
braking distance reserve of the trolley. When this is located within the braking distance reserve,
the trolley can no longer move in the direction of the blocked region. The hoist can lift or lower
without restriction however.
If the corner of a blocked region is approached diagonally, an internal decision is made as to
which drive can continue to move and which must brake based on the distance to go and the
status of the sway control system. Two different constellations are possible here:
● The hoist can continue to lower before the blocked region and the trolley must remain
stationary.
● The trolley can continue to move above the blocked region and the hoist must brake.
It can happen that both drives are braked briefly before a decision is made as to which drive can
continue to move.
Note
Delays can result in overshoots beyond the stopping point. Take this into consideration when
setting the braking distance reserve for the hoist and trolley.
Sway Control function description
6.11 Collision protection - soft approach
SC integrated STS, GSU
Operating Instructions, 07/2019, A5E48271265B AA
185