Festo CPV GEASI-4E3A-Z Series Brief Description page 21

3.5 Connecting the AS-interface bus and the load voltage
Note
The sensor supply derived from the AS-Interface- power
supply is protected against short circuits and overload.
It must not be connected to other voltages (for example
common ground).
The valves must be supplied separately with 24 V via
the load voltage connection.
The AS-interface has an integrated watchdog function
which resets the outputs if there is a bus communica-
tion failure.
Warning
S Use only PELV (protective extra-low voltage) circuits
as per EN 60204-1 for the electric power supply.
S Also observe the general requirements for PELV
power circuits as per EN 60204-1.
S Only use power sources which guarantee reliable
electrical isolation of the operating voltage as per
EN 60204-1.
By the use of PELV circuits, protection against electric
shock (protection against direct and indirect contact) is
guaranteed in accordance with EN 60204-1.
Festo CPV...-GE-ASI-4E3A-... 1108b English 21