Siemens SINUMERIK 840D Function Manual page 874

S3: Synchronous spindle
19.4 Special features
Speed and acceleration limits
The speed and acceleration limits of the spindles operating in synchronous mode are
determined by the "weakest" spindle in the synchronous spindle pair. The current gear stages,
the programmed acceleration and, for the leading spindle, the effective position control status
(On/Off) are taken into account for this purpose.
The maximum speed of the leading spindle is calculated internally in the control taking into
account the speed ratio and the spindle limitations of the following spindle.
Multiple couplings
If the system detects that a coupling is already active for an FS and LS when the synchronous
mode is activated, then the activation process is ignored and an alarm message is generated.
Examples of multiple couplings:
● A spindle is acting as the FS for several LS
● Coupling cascade (an FS is an LS of an additional coupling)
Number of configurable spindles per channel
Every axis in the channel can be configured as a spindle. The number of axes per channel
depends on the control version.
Cross-channel setpoint coupling
● Cross-channel synchronous spindle couplings can be implemented with no additional
restrictions for DV, AV, and VV.
● Any number of following spindles, corresponding to the number of all spindles minus one
spindle for the master, in any channels on an NCU can be coupled to one leading spindle.
Start synchronous mode using ASUB
When the PLC starts an ASUB, in the AUTOMATIC or MDI modes, synchronous operation can
be switched on and off – or terminated.
Further information
Function Manual Basic Functions; Mode group, channel, program mode, reset response
Response to alarms
In the case of an alarm, which occurs during synchronous operation, and acts as alarm
response "withdraw control enable" and "activate follow-up mode" in the control, the ongoing
control behavior is the same as the behavior due to NC/PLC interface signals:
● DB31, ... DBX2.1 = 0 (controller enable)
● DB31, ... DBX1.4 = 1 (follow-up mode)
(See Section "Synchronous mode and NC/PLC interface signals (Page 877)")
By resynchronizing via the NC/PLC interface signal:
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Axes and spindles
Function Manual, 06/2019, A5E47437747B AA