Banner AG4 Series Safety Laser Scanner
Product Manual
P/N 144924 05/2009
41
4.6.4
Access guarding
WARNING . . . FIELD PAIR SWITCHING LIMITATIONS
Field Pair switchover (safety output authority changes) are only permitted during portions of the application cycle where
hazards are not present or are otherwise inaccessible via other guarding means.
Failure to properly control or apply Field Pair switchover operations can result in serious bodily injury or death.
1 Emergency Stop control device and start/restart button
2 Scanner
3 PF, left conveyor line, activated
4 Reference surface of the PF
5 PF, right conveyor line, deactivated
Figure 27. Vertical PF Access guarding
The figure above shows an input and output station with conveyor lanes in a danger zone. In this case three different PFs are used:
Left conveyor lane PF
Right conveyor lane PF
Both conveyor lanes PF
The machine control safety PLC system controls the switchover between the PFs.
PFs can change only when additional measures prevent access to the hazard through the inactive PF. Access can be restricted for example, via
the dimensions of a loaded palette, which makes it impossible to enter the danger zone during the switchover.
The vertical PF of the access guarding only detects people as they pass through. In this case, a start/restart interlock must ensure that the
dangerous movement does not start again automatically.
Scanners with > 40 mm resolution are not suitable for finger, hand and arm detection!