Points To Note - Siemens SINUMERIK 840D sl Function Manual

difference between the positions of the leading and synchronized axes greater than the setting
in the machine data:
MD36030 $MA_STANDSTILL_POS_TOL (standstill tolerance)
In this case, a new setpoint is specified for the synchronized axis (axes) without interpolation.
The positional difference detected earlier is then corrected by the position controller. The
correction causes only the synchronized axis (axes) to move.
The motional sequence of the synchronized axis (axes) is analogous to the situation in which
the grouping switches from the "Hold" state to position control mode. In this case, the position
specified by the position controller before the grouping is halted is set again on condition that
the zero speed monitor has not activated alarm 25040 (with follow-up as alarm reaction) in the
meantime.
The same tolerance window is used for this mode of automatic synchronization as for the zero
speed monitoring function:
MD36030 $MA_STANDSTILL_POS_TOL (standstill tolerance)
Parameter rate dependence loads with machine data:
MD36012 $MA_STOP_LIMIT_FACTOR (exact stop coarse/fine and standstill factor)
Note
The following interface signal blocks automatic synchronization in all modes except referencing
mode:
DB31, ... DBX29.5 (no automatic synchronization)
Should the automatic synchronization be activated at this point, then the following interface
signal must be reset:
DB31, ... DBX29.5 = 0 (no automatic synchronization)
Then switch one of the axes in the gantry grouping from follow-up mode to position-controlled
mode. This is achieved with the interface signals:
DB31, ... DBX1.4 = 1 (follow-up mode)
DB31, ... DBX2.1 = 1 (servo enable)
3.3.3

Points to note

2. Position measuring systems per gantry axis
Different types of position measuring systems can be mounted on the gantry axes of a
grouping. Furthermore, each gantry axis is capable of processing two position measuring
systems, it being possible to switch over from one system to the other at any time:
DB31, ... DBX1.5 (position measuring system 1)
DB31, ... DBX1.6 (position measuring system 2)
The maximum tolerance for position actual value switchover should be set to a lower value
than the gantry warning limit:
Special functions
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
3.3 Referencing and synchronization of gantry axes
G1: Gantry axes
157