Synchronizing Spindle - Siemens SINUMERIK 840D sl Commissioning Manual

NCK start-up
10.6 Parameterization of spindle data
10.6.6

Synchronizing spindle

To allow the spindle to be positioned from the NCK, its position has to be adjusted using the
measuring system. This operation is called "synchronization".
As a rule, synchronizing is done to the zero mark of the connected encoder or to a reference
cam as zero mark substitute.
Machine data
● MD34100 REFP_SET_POS (reference point value)
defines the actual position of the spindle at the zero mark position.
The machine data
● MD34090 REFP_MOVE_DIST_CORR (reference-point offset)
is used to enter the zero mark offset.
Machine data
● MD34200 ENC_REFP_MODE (referencing mode)
specifies via which signal the synchronization takes place:
1 = encoder zero mark
2 = reference cam
When is synchronization necessary?
The spindle will be synchronized:
● after the NC has powered up when the spindle is moved using a programming command
● after a request for resynchronization by the PLC
● after each gear stage change for an indirect measuring system
● when the encoder limit frequency falls below the programmed value after a speed has
178
NST DB31,... DBX16.4 (resynchronize spindle 1)
NST DB31,... DBX16.5 (resynchronize spindle 2)
MD31040 ENC_IS_DIRECT (direct measuring system) = 0
been programmed which is above the encoder limit frequency.
NOTICE
If the spindle encoder is not mounted directly on the spindle and there are gear ratios
between the encoder and spindle (e.g. encoder mounted on motor), then a BERO signal
connected to the drive (SERVO) must be used for synchronization. The control system
then automatically resynchronizes the spindle after each gear stage change. The user
does not have to contribute anything here.
In general, backlash, gearbox elasticity and reference cam hysteresis reduce the
accuracy achievable during synchronization.
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
IBN CNC: NCK, PLC, drive