Siemens SINUMERIK 840Di Function Manual page 1554

Detailed Description
2.3 Configurable gear adaptation
2.3.5 Gear step change at fixed position
Application and advantages
Machine tools increasingly use standardized spindle drives, firstly to save technological dead
time on a gear step change and secondly to gain the cost benefits of using standardized
components.
The Gear step change at fixed position function supports the "directed gear step change" of
load gearboxes that need to be activated in a different way than the NC. The gear step
change can in this case only be performed at a defined spindle position. An oscillation
motion as required by conventional load gearboxes is thus no longer necessary.
Sequence for gear step change at fixed position
Gear step 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 across the position configured in
• After reaching the gear step change position configured in machine data:
• Output of VDI interface signals:
2-50
machine data:
MD35012 $MA_GEAR_STEP_CHANGE_POSITION.
If the gear step change is performed out of a movement, then the current direction of
rotation is maintained. The spindle is in positioning mode during the positioning action.
NC/PLC IS:
DB31, ... DBX84.5 (positioning mode)
is output.
If no reference is available:
DB31, ... DBX60.4/5 = 0
or NC/PLC IS:
DB 31, ... DBX17.4/5 (resynchronize on positioning MS 1/2)
is set, the positioning action is extended by the time it takes to find the zero mark.
MD35012$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 step change dialog starts.
DB31, ... DBX84.6 (oscillation mode)
DB31, ... DBX82.3 (change gear)
DB31, ... DBX82.0-82.2 (set gear step A to C).
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Spindles (S1)