Siemens SINUMERIK 840D sl Function Manual page 898

Synchronous Spindles (S3)
14.4 Special features of synchronous mode
Requirements
Basic requirements for differential speed programming:
● Synchronous spindle functionality is required.
● The dynamic response of the following spindle must be at least as high as that of the
● The differential speed must be programmed in the channel in which the following spindle
● The differential speed must be enabled for the following spindle by the PLC via IS
Note
The differential speed does not therefore affect the coupling process.
The following or leading spindle cannot change gear stages while a coupling is active.
Activate coupling with COUPONC
When the coupling is activated, the following spindle is accelerated, as before, to the leading
spindle speed through application of the coupling factor. If the following spindle is already
rotating (M3, M4) when the coupling is activated, it continues with this motion after coupling.
Deactivate coupling
If the coupling is deactivated, the following spindle continues to rotate at the speed
corresponding to the sum of both speed components. The spindle behaves as if it had been
programmed with the speed and direction transferred from the other spindle. When
deactivating, there are no differences to the previous behavior.
Differential speed
A differential speed results from renewed programming of the following spindle (in the
example S2=... ) or M2=3, M2=4 in speed control mode during an active synchronous
spindle coupling or by adopting the speed of the following spindle with COUONC.
Condition:
Speed S... must also be re-programmed with direction of rotation M3 or M4. Otherwise alarm
16111 "Channel% Block% Spindle% No speed programmed" is displayed.
Read offsets of following spindle
The current offset always changes when a differential speed is programmed. The current
offset can be read at the setpoint end with $AA_COUP_OFFS[Sn] and at the actual value
end with $VA_COUP_OFFS[Sn].
The last offset programmed returns the variable $P_COUP_OFFS[Sn].
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leading spindle. Otherwise, the system may suffer from reduced quality, for example, rigid
tapping without a compensating chuck G331/G332.
is also configured. The leading spindle can be programmed in a different channel.
"Enable overlaid movement" (DB31, ... DBX26.4). If the enable signal has not been set,
alarm 16771 "Channel% Following axis% Overlaid movement not enabled" is output. This
alarm is cleared when IS "Enable overlaid movement" (DB31, ... DBX26.4) is set or the
coupling is terminated.
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Extended Functions