Siemens sinumerik 840D sl Function Manual page 602

Activation during motion
The coupling procedure at different speeds is divided into two phases.
Phase 1
Closure of the coupling is requested with interface signal IS "Master/slave on" (DB31, ...
DBX24.7). The slave spindle accelerates or decelerates along the ramp with the dynamic
response available to it until it reaches the setpoint speed of the master spindle.
When the setpoint speed is reached, the coupling is closed and the interface signal
"Coupling active" (DB31, ... DBX96.7) is set.
If the master spindle is accelerated during the coupling process, the first phase is extended
according to the existing difference in dynamics between the master and slave spindles.
Phase 2
In the second phase, the actual difference speed between the master and slave spindle(s) is
used to generate the following synchronism signals.
NST "Speed tolerance coarse" (DB31, ... DBX96.3)
NST "Speed tolerance fine" (DB31, ... DBX96.2)
The associated limits are defined via the following machine data:
MD37270 $MA_MS_VELO_TOL_COARSE ("Tolerance coarse")
MD37272 $MA_MS_VELO_TOL_FINE ("Tolerance fine").
Note
The "Tolerance coarse" signal can be used to implement a PLC monitoring function that
checks a coupled group for loss of speed synchronism. The "Tolerance fine" signal can be
used to derive the time for mechanical closure of the coupling and to activate the torque
compensatory controller directly.
Special functions: Speed/Torque Coupling, Master-Slave (TE3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
2.1 Speed/torque coupling, master-slave (SW 6 and higher)
Detailed description
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