Siemens SINUMERIK 840D sl Function Manual page 170

G1: Gantry axes
2.6 Miscellaneous points regarding gantry axes
Axis replacement
All axes in the gantry grouping are released automatically in response to a RELEASE
command (leading axis).
A replacement of the leading axis of a closed gantry grouping is only possible, if all axes of
the grouping are known in the channel in which they are to be transferred, otherwise alarm
10658 is signaled.
No automatic axis change and no automatic adjustment of the gantry axis conditions are
undertaken while trying to reconnect a gantry grouping is released with
MD37140 $MA_GANTRY_BREAK_UP = 1. The user is responsible for this. A check of the
axis conditions is conducted after the break up and if necessary, a corresponding alarm
10658 is output.
Note
If a gantry grouping is to be closed again, the user must ensure that all axes of the grouping
are in a channel with a corresponding axis condition.
Default for RESET
In an active gantry grouping, the following MD parameterization is ignored for the
synchronized axes:
MD30450 $MA_IS_CONCURRENT_POS_AX = 1 (Reset default: neutral axis/channel axis)
The state of the leading axis is assumed. The user is informed about the inappropriate
configuration with display alarm 4300.
Display data
The position actual value display shows the actual values of both the leading axis and the
synchronized axes. The same applies to the service display values in the "Diagnosis"
operating area.
Software limit switch
The SW limit switch monitor is processed for the leading axis only. If the leading axis crosses
the limit switch, all axes in the gantry grouping are braked to a standstill.
Differences in comparison with the "Coupled motion" function
The main differences between the "gantry axes" and "coupled motion" functions are listed
below:
• The axis coupling between the gantry axes must always be active. Separation of the axis
coupling via part program is therefore not possible for gantry axes. In contrast, the coupled
axis grouping can be separated by means of the part program and the axes then traversed
individually.
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Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Special Functions