Siemens SINUMERIK 828D Function Manual page 117

A3: Axis Monitoring, Protection Zones
2.3 Protection zones
Preactivation
Only preactivated protection zones can be activated from the PLC user program.
Figure 2-13 Example: Turning machine with preactivated protection zone for a sensor.
Preactivation with conditional stop
In the case of preactivation with condition stop, the system does not always stop in front of a preactivated
protection zone which has been violated. The stop only occurs if the protection zone has been activated. This
facilitates uninterrupted processing if the protection zones have only been activated in special cases. N.B. The
system may move into the protection zone as a result of the braking ramp if the protection zone is only activated
immediately prior to positioning.
Deactivation
A protection zone can be deactivated from a part program. Additionally an active, preactivated protection zone
can be set again in the preactivated (= ineffective) state through the PLC user program.
RESET response
The activation status of a protection zone is retained even after NC-RESET and program end.
Memory requirements
The memory requirement of the persistent memory is determined with following machine data :
MD18190 $MN_MM_NUM_PROTECT_AREA_NCK (Number of available machine-defined protection zones)
MD28200 $MC_MM_NUM_PROTECT_AREA_CHAN (Number of available channel-defined protection zones)
The memory requirement in the dynamic part with regard to the protection zones is established with following
machine data :
MD28210 $MC_MM_NUM_PROTECT_AREA_ACTIVE (Maximum number of protection zones that can be
activated simultaneously in the channel)
MD28212 $MC_MM_NUM_PROTECT_AREA_CONTUR (Maximum number of definable contour elements per
protection zone)
Basic Functions
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Function Manual, 09/2011, 6FC5397-0BP40-2BA0