Siemens SINUMERIK 840D sl Function Manual page 171

• In the "Gantry Axes" function, the difference of the actual position values from the leading
and synchronized axis is monitored continuously and the traversing motion is shut down if
there are impermissible deviations. There is no monitoring for the "Coupled motion"
function.
• Gantry axes must remain coupled even during referencing. For this reason, special
procedures are applied for the reference point approach of gantry axes. In contrast,
coupled-motion axes are referenced as individual axes.
• For the gantry axes to traverse without mechanical offset, the synchronized axes must be
set like the leading axes from the control dynamics perspective. In contrast, the "coupled
motion" function permits axes with different dynamic control response characteristics to be
coupled.
References:
Function Manual, Basic Functions, Reference Point Approach (M3)
Block search with active coupling
Note
For an active coupling, it is recommended to only use block search type 5, "Block search via
program test" (SERUPRO) for a block search.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
2.6 Miscellaneous points regarding gantry axes
G1: Gantry axes
171