Siemens SINUMERIK 840D sl Function Manual page 943

Indexing axes are generally traversed in JOG mode (standard setting). Continuous mode
plays a less important role.
If the operator changes the direction of traversing before the indexing position has been
reached, the indexing axis is positioned on the next indexing position in the direction of
traversing. The traversing movement must be started in the opposite direction.
For further information on continuous traversing in jog or continuous mode, please see:
References:
/FB2/ Function Manual, Extended Functions; Manual and Handwheel Travel (H1)
Incremental traversal in JOG mode (INC)
Irrespective of the current increment setting (INC1, ..., INCvar), the indexing axis always
traverses through one indexing position in the selected direction when a traversing key "+" or
"-" is pressed.
In jog mode, the traversing movement is interrupted when the traversing key is released. The
indexing position can be approached by pressing the traversing key again.
In continuous mode, the traversing movement is interrupted when the traversing key is
pressed again. The indexing axis is, in this case, not located on the indexing position.
Between indexing positions
If an indexing axis is situated between 2 indexing positions, then it approaches the next-
higher indexing position when the "+" traversing key is pressed in JOG-INC mode. Similarly,
pressing the "-" traversing key causes the next-lower indexing position to be approached.
Handwheel traversal
When the indexing axis is traversed by means of the handwheel in JOG mode, the indexing
positions are ignored. As the handwheel is turned, the indexing axis moves to any position
depending on the basic system in mm, inches or degrees.
If traversing of the indexing axis with the handwheel is to be interlocked, this can be handled
by the PLC user program.
Signal from PLC "Indexing axis in position"
During the traversing motion of the indexing axis in the JOG mode, the following NC/PLC
interface signal displays the reaching of the indexing position:
DB31, ... DBX76.6 (indexing axis in position)
Prerequisite: The indexing axis is referenced (DB31, ... DBX60.4 and 5 = 1)
Alarms in JOG mode
If the indexing axis leaves the traversing range defined in the indexing position table when
traversing in JOG mode, alarm 20054 "wrong index for indexing axis in JOG" is output.
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
T1: Indexing axes
16.2 Traversing of indexing axes
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