Siemens SINUMERIK 840D sl Function Manual page 830

Detailed description
2.3 Coordinate systems
Overlaid movements
The "Superimposed motion" for the programmed axis can only be accessed from
synchronized actions via the system variable $AA_OFF[axis].
Run-up
After run-up (POWER ON) the last used offset values for the "Zero offset external" are
stored and do not become effective again until there is a renewed activation signal.
System frames are retained during Power ON, depending on the following machine data:
MD24008 $MC_CHSFRAME_POWERON_MASK (reset system frames after Power On)
RESET/end of program
The activated values remain active after RESET and program end.
Reset response of channel-specific system fames as follows:
The system frame for the "external zero offset" is active after RESET with the following
machine data setting:
MD24006 $MC_CHSFRAME_RESET_MASK, Bit 1 = 1
The "external zero offset" in the active system frame is deleted in the data management
through the following machine data setting:
MD24006 $MC_CHSFRAME_RESET_MASK, Bit 1 = 0
The following frames are active after RESET:
• System frame for:
Suppression
The NC program instruction SUPA suppresses the "Zero offset external" while the block is
being processed.
The command G74 (reference point approach) and the equivalent operator actions in
"Reference point approach" mode suppress the "Zero offset external" for the duration of the
reference point approach.
With G74, i.e., "Automatic" or "MDA" mode, the previously active "Zero offset external"
automatically becomes active again with the next traverse motion in the block.
After a mode change from "Reference point approach" mode, the VDI signal for the
referenced axes must be set for reactivation.
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MD24006 $MC_CHSFRAME_RESET_MASK, Bit 4 = 1 (workpiece reference point)
MD24006 $MC_CHSFRAME_RESET_MASK, Bit 5 = 1 (cycles)
Basic logic functions: Axes, coordinate systems, frames (K2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0