Lenze 931K - Manual (Page 111)

Operating modes
Positioning
Functional description
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111 KHB 13.0002−EN 4.1
9.4.3 Functional description
There are two ways to transfer a target position to the drive controller:
ƒ Simple travel task
When the drive controller has reached a target position, it signals this to the master with
the target_reached bit (bit 10 in the status word object). In this operating mode, the drive
controller stops when it has reached the target.
ƒ Sequence of travel tasks
After the drive controller has reached a target, it immediately starts to approach the next
target.
Interruption of a running task by a new travel task
The running positioning task is interrupted immediately and the new travel task is started.
These three methods are controlled by the new_set_point and change_set_immediately
bits in the control word object and by the set_point_acknowledge bit in the status word
object. The relationship between these bits is an interrogation/ response relationship. This
makes it possible to prepare a new travel task while the old one is still running.
(1)
1
1
1
(2)
(3)
(4)
(5)
(6)
(7)
t
t
t
data_
valid
new_
set_
point
set_
point_
acknowledge
931e_406
Fig. 21 Transfer of a travel task between master and drive controller
First the positioning data (target position, travelling speed and acceleration) are
transferred to the drive controller. When the positioning data record is written completely
(1), the master can start the positioning by setting the new_set_point bit in the control
word to "1" (2).
After the drive controller has recognised the new data and transferred this data into its
buffer, the controller signals this to the master by setting the set_point_acknowledge bit
in the status word (3).
Then the master can start to write a new positioning data record to the drive controller (4)
and delete the new_set_point bit again (5). The drive controller signals that it is ready to
accept a new travel task (6) by setting the set_point_acknowledge bit to "0". Prior to this,
the master may not start a new positioning (7).
In Fig. 22 a new positioning is only started if the last positioning has been completed
completely. For this purpose, the master evaluates the target_reached bit in the status