Siemens SINUMERIK 840D sl Function Manual page 142

A3: Axis Monitoring, Protection Zones
3.3 Protection zones
Preactivated protection zones are displayed via the following NC/PLC interface signals:
● DB21, ... DBX272.0 - 273.1 == 1 (machine-related protection zone 1 - 10 preactivated)
● DB21, ... DBX274.0 - 275.1 == 1 (channel-specific protection zone 1 - 10 preactivated)
Figure 3-13
Preactivation with conditional stop
NOTICE
Protection zone violation possible
If a preactivated protection zone with conditional stop is not activated in good time, the NC
may no longer be able to stop before the protection zone in good time because the braking
distance after the activation point has not been taken into account.
The preactivation of protection zones with conditional stop is performed in the part program
via:
CPROT or NPROT (<protection zone number>, 3)
In the case of a preactivated protection zone with conditional stop, a traversing motion is not
stopped before this if the traversing motion goes into the protection zone. A stop is only
performed when the protection zone has been activated. This behavior is to enable
uninterrupted machining controlled by the user when the protection zone is only required
temporarily.
Deactivation via part program
A protection zone that has been activated via the part program or an NC/PLC interface signal
can be deactivated again at any time from the part program with status = 0:
● Channel-specific protection zone:
CPROT(n, 0)
● Machine-specific protection zone:
NPROT(n, 0)
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Example: Turning machine with preactivated protection zone for a sensor.
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions