Siemens sinumerik 840D sl Function Manual page 162

Detailed description
2.5 Miscellaneous points regarding gantry axes
Axes of a gantry grouping must not be known in all channels. The check is not performed
when powering up, but only when an attempt is made to replaced the master axis in the
channel.
When it is attempted to close a cancelled gantry grouping with the following machine data
there will be no automatic axis replacement nor any automatic dynamic response adaptation
of the axes:
MD37140 $MA_GANTRY_BREAK_UP (invalidate gantry grouping)
The user is responsible for this. However, a check of the axes states is performed after
break-up and, if necessary, alarm 10658 is issued. If a gantry grouping is to be closed again,
the user must ensure that all axes of the grouping are in one channel with the appropriate
axis state.
MD30450 $MA_IS_CONCURRENT_POS_AX=1 (Reset default: neutral axis/channel axis)
With active gantry grouping, the MD is ignored for the slave axes. The state of the master
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. It is therefore not
• With "gantry axes", the difference between the position actual values of the leading and
• Gantry axes must remain coupled even during referencing. For this reason, special
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possible to separate the axis coupling between "gantry axes" by means of the part
program. In contrast, the coupled axis grouping can be separated by means of the part
program and the axes then traversed individually.
synchronized axes is continuously monitored and the traversing motion terminated in
response to illegal deviations. No such monitoring takes place with the "coupled motion"
function.
procedures are applied for the reference point approach of gantry axes. In contrast,
coupled-motion axes are referenced as individual axes.
Special functions: Gantry Axes (G1)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0