Siemens SINUMERIK 828D Function Manual page 716

K2: Axis Types, Coordinate Systems, Frames
10.4 Coordinate systems
Effect of activation
The offset for an axis becomes active when the first motion block for this axis is executed after the offset is
activated.
Example of possible chronological sequence:
G0 X100
X150 ; A new "Zero offset external" is activated by the PLC during this
motion.
X200 ; The new "Zero offset external" is applied due to G0 programming at the
end of the block (X200), if no velocity reserve is available (100%).
The "Zero offset external via system frame" is applied immediately.
Channel-specific system frames can be configured through the following machine data:
MD28082 $MC_MM_SYSTEM_FRAME_MASK (System frames SRAM)
Programming
Setting a new offset via the axis-specific system variables:
$AA_ETRANS[axis]=R
i
The instruction below reads the axis­specific active offset value:
R =$AA_ETRANS[axis]
i
Note
The read value can then differ from the previously set value, if the set value has not yet been
activated.
The read value corresponds to a value set previously, if the most recently set value has not
yet been activated. The system frame for the "Zero offset external" exists only if it has been
configured.
DRF offset
The DRF offset enables the adjustment of an additional incremental zero offset for geometry and additional axes
in the basic coordinate system through handwheel.
The DRF offset can be read via the axis-specific system variable:
$AC_DRF[<Axis>]
References:
/FB2/ Function Manual of Extension Functions; Jog with/without Handwheel (H1),
Section: DRF offset
Overlaid movements
The "Superimposed motion" for the programmed axis can only be accessed from synchronized actions via the
system variable $AA_OFF[axis].
716
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions