Loop Traverse To A Target At The Software Limit Switch End - Siemens SIMATIC FM 351 Installation Manual

Operating Modes and Settings
Requirements
Example
9
9-18
Take note of the following requirements for a loop traverse:
If you have parameterized a loop traverse against the traverse direction to
the target, the target position which can be approached at a maximum is
located at:
– With positive traverse direction
1
Target < SLE - / Target range - Negative switch-off difference -
2
Positive switchover difference
– With negative traverse direction
1
Target > SLS + / Target range + Positive switch-off difference +
2
Positive switchover difference
A loop traverse is not executed if the target is approached in the direction
of the loop traverse.
If you have parameterized a loop traverse in the traverse direction to the
target, the target position which can be approached at a maximum is lo-
cated at:
– With positive traverse direction
1
Target < SLE -
/ Target range
2
– With negative traverse direction
1
Target > SLS + / Target range
2
The figure below shows you the position of the fictitious target based on
positioning with loop traverse to the maximum target position in the positive
direction.
v
rapid
v
creep
-v
creep
Switchover difference, negative
1
Figure 9-4 Loop Traverse to a Target at the Software Limit Switch End
Fictitious target
2
Target
1
2 Switch-off difference, positive
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
3
Change of
direction
3