Festo CPV-ASI-8E8A-ZCE Series Brief Description page 10

3.5 Connect the AS-Interface bus and the load voltage
Note
The sensor supply derived from the AS­Interface­power
supply is protected against short circuits and overload.
It must not be connected to other voltages (for example
common ground).
The power supply for the valves (outputs) is provided
by the additional supply: 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 the bus communication
fails.
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 power units, protection against electric
shock (protection against direct and indirect contact) is
guaranteed in accordance with EN 60204-1.
10 Festo CPV-ASI-8E8A-Z-CE 2018-11b English