Siemens SINUMERIK 840D sl Function Manual page 1656

Detailed Description
2.3 Configurable gear adaptation
Permanently defining the gear step with M41 to M45
The gear step can be permanently defined in the part program with M41 to M45.
If a gear step is specified by M41 to M45, which is not the same as the current (actual) gear
step,
NC/PLC IS:
DB31, ... DBX82.3 (Change gear)
and
DB31, ... DBX82.0-82.2 (Set gear step A to C)
are set.
The programmed spindle speed (S value) then refers to this permanently defined gear step.
If a spindle speed is programmed, which exceeds the max. speed of the defined gear step,
the spindle speed is limited to the max. speed of the gear step:
MD35130 $MA_GEAR_STEP_MAX_VELO_LIMIT
and NC/PLC IS:
DB31, ... DBX83.1 (Setpoint speed limited)
is set.
Block change
When programming the gear step change in the part program, the gear step change set
remains active until the gear step change is aborted by PLC. (Same effect, as if NC/PLC IS:
DB21, ... DBX6.1 (Read-in enable)
is set.)
Specification of gear step via PLC with FC18
The gear step change can also be performed by function block FC18 during a part program,
in the reset state or in all operating modes.
If the speed and direction of rotation is specified with FC18, the NC can be requested to
select the gear step as appropriate for the speed. This corresponds to an automatic gear
step change with M40.
The gear step is not changed if the spindle is positioned by FC18 or if traversing in axis
mode.
Further instructions on function block FC18 can be found under:
Literature:
/FB1/ Function Manual Basic Functions; PLC Basic Program (P3)
Specification of gear step with synchronized actions
The gear step change can be requested by synchronized actions:
• In the event of automatic gear step change forM40 with S
• When specifying gear steps 1 to 5 with M41 to M45.
The gear step is not changed if the spindle is positioned by synchronized actions or if
traversing in axis mode.
46
Or
Basic logic functions: Spindles (S1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0