BECKHOFF CX50x0 - Manual (Page 6)

Safety instructions
2 CX50x0 units in potentially explosive areas
1.2 Safety instructions
1.2.1 Delivery state
All the components are supplied in particular hardware and software configurations appropriate for the
application. Modifications to hardware or software configurations other than those described in the
documentation are not permitted, and nullify the liability of Beckhoff Automation GmbH.
1.2.2 Operator's obligation to exercise diligence
The operator must ensure that
 the Beckhoff Fieldbus Components are only used as intended (see chapter Special conditions in
potentially explosive areas).
 the Beckhoff Fieldbus Components are only operated in sound condition and in working order.
 the Beckhoff Fieldbus Components are maintained repaired only by suitably qualified and authorized
personnel.
 the personnel is instructed regularly about relevant occupational safety and environmental protection
aspects, and is familiar with the operating manual and in particular the safety notes contained herein.
 none of the safety and warning notes attached to the Beckhoff Fieldbus Components are removed, and
all notes remain legible.