Siemens SINUMERIK Series Function Manual page 779

Display of indexing position
The number of the indexing position programmed last can be read with the following system
variables:
$AA_PROG_INDEX_AX_POS_NO
The number of the indexing position traversed last can be displayed with the following
system variables:
$AA_ACT_INDEX_AX_POS_NO
The display depends on the setting in machine data:
MD10940 $MN_INDEX_AX_MODE (settings for indexing position)
Bit
0
The following graphics will illustrate the difference between Bit 0 = 0 and Bit 0 = 1:
Figure 15-1
Extended Functions
Function Manual, 03/2013, 6FC5397-1BP40-3BA1
Value Meaning
0 The indexing position changes when the indexing position is reached ("exact stop
fine" window) and remains unchanged until the next indexing position is reached. The
indexing area thus begins at one indexing position and ends in front of the next
indexing position.
1 The indexing position changes when half the indexing position is reached.
A quasi-symmetrical indexing area is thus applied around the indexing position
(symmetrical only on linear axes with equidistant indexing or modulo rotary axes on
which the indexing area is an integer multiple of the modulo range (MD30330
$MA_MODULO_RANGE), otherwise proportional to the distances between the
indexing positions).
On modulo rotary axes, the area between the last indexing position and the first
indexing position is divided proportionally based on the lengths of the first indexing
area and the last indexing area.
Indexing position displays: Linear axis
T1: Indexing axes
15.4 Programming of indexing axes
779