Siemens SINUMERIK 840D Function Manual page 800

S1: Spindles
18.4 Configurable gear adaptations
The "Gear stage change at fixed position" function supports the "directed gear stage change"
of load gearboxes that need to be activated in a different way than the NC. The gear stage
change can in this case only be performed at a defined spindle position. An oscillation
movement as required by conventional load gearboxes is thus no longer necessary.
Sequence for gear stage change at fixed position
The gear stage change at fixed position
Machine data configuration:
MD35010 $MA_GEAR_STEP_CHANGE_ENABLE = 2
runs the following sequence:
● Positioning of the spindle from standstill or movement to the position configured in machine
data:
MD35012 $MA_GEAR_STEP_CHANGE_POSITION.
If the gear stage change is performed out of a movement, then the current direction of
rotation is maintained. The spindle is in positioning mode during the positioning action.
NC/PLC IS:
DB31, ... DBX84.5 (positioning mode)
is output.
If no reference is available:
DB31, ... DBX60.4/5 = 0
or NC/PLC IS:
DB31, ... DBX17.4/5 (resynchronize on positioning MS 1/2)
is set, the positioning action is extended by the time it takes to find the zero mark.
● After reaching the gear stage change position configured in machine data:
MD35012$MA_GEAR_STEP_CHANGE_POSITION
the machine waits for the time in machine data:
MD35310 $MA_SPIND_POSIT_DELAY_TIME
before switching to oscillation mode,
and the known gear stage change dialog starts.
● Output of NC/PLC interface signals:
DB31, ... DBX84.6 (oscillation mode)
DB31, ... DBX82.3 (change gear)
DB31, ... DBX82.0-82.2 (set gear stage A to C).
● Position control is not disabled when an active measuring system with indirect encoder
(motor encoder) is used:
MD31040 $MA_ENC_IS_DIRECT = 0
If a measuring system with a direct encoder (load encoder) is active, position control is
deactivated:
DB31, ... DBX61.5 = 0,
because the induction flux to the load is interrupted and closed-loop position control is no
longer possible.
● If position-controlled operation is not possible, it can be disabled by
resetting "Controller enable":
DB31, ... DBX2.1 = 0
.
800
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA