Siemens SINUMERIK 840D sl Function Manual page 1701

Maximum encoder limit frequency unudershot
If the maximum encoder frequency limit has been exceeded and the speed subsequently
falls below the maximum encoder limit frequency (smaller S value programmed, spindle
offset switch changed, etc.), the spindle is automatically synchronized with the next zero
mark or the next Bero signal. The new synchronization will always be carried out for the
active position measuring system that has lost its synchronization and whose max. encoder
limit frequency is currently undershot.
Special points to be noted
If the following functions are active, the maximum encoder frequency cannot be exceeded:
• Spindle positioning mode, axis mode
• Thread cutting (G33, G34, G35)
• Tapping without compensating chuck G331, G332 (does not apply to G63)
• Revolutional feedrate (G95)
• Constant cutting rate (G96, G961, G97, G971)
• SPCON
2.6.6 End point monitoring
End point monitoring
During positioning (the spindle is in positioning mode), the system monitors the distance
from the spindle (with reference to the actual position) to the programmed spindle position
setpoint (end point).
For this to work, in machine data:
MD36000 $MA_STOP_LIMIT_COARSE (Exact stop limit coarse)
and
MD36010 $MA_STOP_LIMIT_FINE (Exact stop limit fine)
two limit values can be defined as an incremental path starting from the spindle position
setpoint.
Regardless of the two limit values, the positioning of the spindle is always as accurate as
defined by the connected spindle measurement encoder, the backlash, the transmission
ratio, etc.
Basic logic functions: Spindles (S1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed Description
2.6 Spindle monitoring
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