Siemens SINUMERIK 840D sl Function Manual page 89

Activation
The actual-velocity monitoring is activated as soon as the active measuring system returns
valid actual values (encoder limit frequency not exceeded):
DB31, ... DBX1.5/1.6 (position measuring system 1/2)
Effectivity
The actual-velocity monitoring only operates with active position control and the following
axis types:
• Linear axes
• Rotary axes
• Open loop controlled and position controlled spindles.
Fault
If the threshold is exceeded, the following alarm appears:
25030 "Axis <Axis identifier> Actual-velocity alarm limit"
The affected axis is stopped via the configured braking ramp in follow-up mode:
MD36610 $MA_AX_EMERGENCY_STOP_TIME
(Maximum time for braking ramp when an error occurs)
2.1.5 Measuring-system monitoring (systems with SIMODRIVE 611D)
2.1.5.1 Encoder-limit-frequency monitoring
Function
The encoder-limit-frequency monitoring checks that the encoder frequency does not exceed
the configured encoder limit frequency.
MD36300 $MA_ENC_FREQ_LIMIT (encoder limit frequency)
Encoder-limit-frequency monitoring always refers to the active measuring system selected in
the NC/PLC interface:
DB31, ... DBX1.5/1.6 (position measuring system 1/2)
Effectivity
The encoder limit frequency is operative for:
• Linear axes
• Rotary axes
• Open loop controlled and position controlled spindles.
Basic logic functions: Axis monitoring, protection zones (A3)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed description
2.1 Axis monitoring
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