Effects On Existing Functions - Siemens SINUMERIK 840C Installation Instructions Manual

03.95
12.30.6

Effects on existing functions

Master/slave operation does not cause any function restrictions in the master except for the
alarm handling described in the previous section. For the slave, the following changes must be
taken into account because speed/torque coupling is used instead of NC-controlled motion
setpoints:
• Zero-speed and contour monitoring are deactivated.
• The PLC status information traverse command +/- is not updated.
• In the NC service display, only the absolute actual position, the speed setpoint (0.01%)
and the partial actual value need be correctly updated. If the slave drive is a GI following
axis or a following spindle the error synchronism is also updated. Other information such
as the following error are modelled or generated from the NC setpoint that is not relevant
to the real motion of the axis/spindle.
• In slave operation, no compensations should be active. The individual effects are:
– Quadrant error compensation: the correction value from the master is transferred to
the slave via the speed setpoint coupling. The compensation value of the slave is not
used.
– Tacho compensation: the tacho compensation is deactivated internally.
– Leadscrew error compensation, interpolatory compensation with absolute values: This
actual value is still corrected but not used for control.
– Backlash compensation corrects the actual value in accordance with the setpoint from
the NCK and is therefore automatically inactive. Depending on the traverse motion of
the master, the actual position is therefore incorrect by the amount of the backlash.
After the backlash compensation has been written, the interface signal "Reference
point reached" is cleared.
– Semi-automatic drift compensation: In slave operation, the drift is always calculated
with respect to 0. This function must not be activated by the user during slave
operation.
• A mode change might possibly not be performed (see Section "Activation/Deactivation").
• The ramp function generator rapid stop function from the PLC in the slave is ignored in the
speed setpoint. The ramp function generator rapid stop function from PLC in the master
causes rapid stop of the slaves via the speed setpoint coupling. The PLC signal in the
Master of the torque compensation controller, MD 1340*/2701* is decisive for deactiva-
tion of the torque compensation controller. This might be another slave in a chain configur-
ation (see Section "Function description"). It is therefore advisable to activate the ramp
function generator rapid stop signal from the PLC (DB29, DB31) for all axes/spindles of a
master/slave grouping simultaneously.
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
6FC5197- AA50
12 Functional Descriptions
12.30.6 Effects on existing functions
12–311