Siemens SIMATIC ET 200AL System Manual page 28

Supply voltages
Provide the IO-Link master with an SELV/PELV 1L+ supply voltage.
The SELV/PELV 2L+ load voltage is supplied via the M12-A connector with port class B or via
the M12-L power connector. The SELV/PELV 2L+ load voltage can be switched depending on
the application.
• IO-Link 1L+ supply voltage (non-switched) via M12-A connector port class A.
• IO-Link 2L+ load voltage (switched) via M12-A connector port class B or M12-L power
connector.
Safe electrical isolation (SELV/PELV)
Power packs/power supply modules with safe electrical isolation SELV/PELV are required for
operation of the IO-Link I/O modules. These power packs/power supply modules must comply
with IEC 61010-2-201.
The wiring of SELV/PELV circuits must be separated from the wiring of non-SELV/PELV circuits.
Or the insulation of all conductors must be rated for the higher voltage.
NOTICE
Operation in damp / wet environments
When operating in a damp / wet environment, different voltage limits apply for SELV/PELV
according to IEC 61010-2-201.
Configuring IO-Link I/O modules with grounded reference potential
In the configuration of IO-Link I/O modules with grounded reference potential, any
interference currents that occur are discharged to functional ground. The connections must
be externally connected. Establish a connection between 1M or 2M and functional ground.
Configuring IO-Link I/O modules with ungrounded reference potential
In the configuration of IO-Link I/O modules with ungrounded reference potential, any
interference currents that occur are discharged to functional ground via an internal RC
network. You do not need an external connection between 1M, 2M and functional ground.
IO-Link I/O modules
System Manual, 10/2020, A5E48755395-AA
5.2 Operation of the IO-Link I/O modules on a grounded/ungrounded infeed
Connecting
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