Siemens SIMATIC FM 351 - Incremental Operating Mode

8
8-17
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
8.7 Incremental Dimensions
Incremental dimensions are specified target values which can be approached
by the FM 351 with the relative or absolute incremental operating mode.
You have the possibility of entering a maximum of 100 incremental dimen-
sions in a table.
When entering the incremental dimensions, please note the following re-
quirements:
 The target that is to be approached must:
– Be more positive than the Software Limit Switch Start plus half the
target range
and
– Be more negative than the Software Limit Switch End minus half the
target range.
SLS SLE
0
Range in which targets may be located
Working range
1
2
 target range
1 2
Tar-
get
Tar-
get
 target range
No target may be located in this part of the working range.
Figure 8-1 Limits for Entry of Incremental Dimensions
Depending on which incremental mode you select, the FM 351 interprets the
value differently.
 Absolute incremental mode: The incremental dimensions are interpreted
as absolute target positions in the coordinate system.
 Relative incremental mode: The incremental dimensions are interpreted
as differences in displacement from the start position.
Definition
Requirements for
Incremental
Dimensions
Interpretation of
the Incremental
Dimensions
Machine Data and Increments