Activating/Deactivating The Master/Slave Torque Compensation Control - Siemens SINUMERIK 840C Installation Instructions Manual

12 Functional Descriptions

12.30.4 Activating/deactivating the master/slave torque compensation control

12.30.4 Activating/deactivating the master/slave torque
compensation control
Master/slave operation is activated and deactivated via the PLC signals in the DB32 or DB31
of the slave in question. In this way, it is possible to achieve both power-on functionality and
switchability using the PLC user program.
Alternatively, it is possible to configure slave operation to take effect straight after power-on
with bit 4 of MD 1812*/523*. This setting is only intended for the power gain application
described above. This mode can only be deactivated by reparameterization of the bits followed
by Power Off.
The feedback signal "Slave operation active" is placed in status word DB31/DB32 for spindle
or axis. A traverse command for a slave axis causes an alarm. After deactivation of slave
operation, it is possible to traverse the axis again (in the part program: matching the actual
position with G200).
With the exception of the function generator operation on the SIMODRIVE 611D, the slave
follows all motions of the master drive with speed coupling. For the master, it is therefore still
possible to select all modes. The switchover to slave mode via the PLC signal is only
possible in certain modes. These are the main modes:
• Control mode
• (C)-axis mode
• (C)-axis mode with GI
• Synchronous spindle following mode
Switchover is not allowed in:
• Oscillating mode
• Positioning mode (M19)
• Function generator mode
• During motion to a fixed stop.
In the last modes, a request for slave operation by the PLC signal is ignored. The request is
ignored and the status bit "Slave operation active" is not set.
In the opposite case, the same procedure is followed, i.e. the mode master/slave first selected
is retained. A function generator start is rejected. A request to travel to fixed stop and a mode
change of the slave to reciprocation or position mode causes alarm 1056* and 2086*.
A mode change to spindle/C-axis mode is permissible, the user must make sure that the
various machine data and PLC control signals are active.
If traversing to a fixed stop is selected in the master, it is necessary to ensure that the torque
compensation controller sets the torque of the slave such that it maintains the parameterized
torque ratio with the master statically, but that the slave is able to output much higher torques
dynamically. However, this is only possible if the output of the torque compensation controller
is set to the output of the slave (Bit 5 in MD 1812*/523*=1).
If a GI coupling of the two axes exists in addition to master/slave operation, synchronism
monitoring remains active. The position reference can thus be checked by the user. The same
applies to synchronous spindle operation. If correctly configured, switchover between following
axis/following spindle operation and slave operation is performed smoothly until the
synchronism error is eliminated.
If master/slave torque compensation control is active, the compensation controller must be
deactivated because synchronism deviations cannot be eliminated. An integral-action in the
compensation controller would then drift away and cause synchronism errors when the gear
coupling is reactivated (master/slave deactivation).
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SINUMERIK 840C (IA)