Gear Stage Change At Fixed Position - Siemens SINUMERIK 840D Function Manual

t :
3
t :
4
*:
Figure 18-6
Boundary conditions
● The NC/PLC interface signal does not have to be set in order to brake the spindle:
DB31, ... DBX4.3 (spindle stop)
The spindle is brought to a standstill in the control system when a gear stage switchover is
requested.
● The gear stage switchover must always be exited by setting the NC/PLC interface signal:
DB31, ... DBX16.3 = 1 (gear stage is changed)
● Oscillation motion in the NC is stopped when the NC/PLC interface signal is reset.
DB31, ... DBX18.5 (oscillation enable)
However, the spindle remains in the "Oscillation mode" mode.
● Spindle synchronization is lost for gear stage switchover and indirect measuring system
(MD31050 $MA_ENC_IS_DIRECT = 0 motor encoder).
Gear stage switchover ⇒ DB31, ... DBX60.4 / 5 = 0 (referenced/synchronized)
The spindle is again automatically synchronized when the zero mark is passed the next time
after a gear stage switchover.
18.4.8

Gear stage change at fixed position

Application and advantages
Machine tools increasingly use standardized spindle drives, firstly to save technological dead
time on a gear stage change and secondly to gain the cost benefits of using standardized
components.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
The gear stage at the machine was switched over.
The PLC user program signals the switchover to the NC and deletes the oscillation mode enable:
● PLC → NC: DB31, ... DBX16.0 - 2 = 2 (actual gear stage)
● PLC → NC: DB31, ... DBX16.3 = 1 (gear stage has been switched over)
● PLC → NC: DB31, ... DBX18.5 = 0 (oscillation enable)
The NC exits the gear stage switchover by resetting the request to the PLC and the oscillation by
switching over the spindle mode from oscillation mode to control mode:
● NC → PLC: DB31, ... DBX82.3 = 0 (switchover gear stage)
● DB31, ... DBX84.6 = 0 (active spindle mode: oscillating mode)
● DB31, ... DBX84.7 = 1 (active spindle mode: control mode)
The NC enables the next block for machining, and accelerates the spindle to the new S value
S1300.
The internal feed disable is set if:
● Gear stage switchover as a result of programming the S value in the NC program AND
● A machiningblock is active (not rapid traverse G0)
Note
The internal feed disable is not set during a gear stage change from synchronized actions or in the
case of specifications via the PLC with FC 18.
Gear stage change with stationary spindle
S1: Spindles
18.4 Configurable gear adaptations
799