Customized Error Reactions - Siemens SINUMERIK 840D sl Function Manual

A3: Axis Monitoring, Protection Zones
3.2 Axis monitoring functions
Fault
Alarm 25020
If the plausibility check is tripped in the active measuring system, alarm 25020 is displayed:
"Axis <Axis name> Zero-mark monitoring active encoder"
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)
Alarm 25021
If the plausibility check is tripped in the passive measuring system, alarm 25021 is displayed:
"Axis <Axis name> Zero-mark monitoring passive encoder"
There is no further alarm response.
Note
In the event of a fault, the adjustment of the absolute encoder is lost and the axis is no longer
referenced. The absolute encoder must be readjusted (see Section "Referencing with absolute
encoders (Page 1179)").
Note
Errors in the incremental track that cannot be detected with amplitude monitoring can cause
position deviations in the millimeter range. The deviation depends on the lattice pitch/line count
and the traversing velocity of the axis when the error occurs.
Complete position monitoring is only possible through redundancy, i.e. through comparison
with an independent second measuring system.
3.2.5.3

Customized error reactions

Customized zero-mark monitoring
The default alarm and reaction behavior of the zero-mark monitoring can be adapted in
absolute measuring systems (MD30240 $MA_ENC_TYPE = 4) with the aid of system
variables. This allows you to perform your own monitoring using a synchronized action or OEM
application and to use all of the reaction options available in this application, e.g.:
● Transmit alarm
● Use cycles (e.g. approach tool-change position)
● ...
Example:
Users can adjust the alarm and reaction behavior so that when machining an expensive
workpiece, which could be damaged if the axis is stopped as a result of an alarm, machining
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Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions