Siemens SIMATIC ET 200AL System Manual page 122

Maintenance
12.1 Replacing modules
Replacing modules
Replacing a module is not permitted during ongoing operation.
Material damage can occur
If you remove/insert modules with the power connected, this can lead to undefined states in
your system.
Material damage to the ET 200AL distributed I/O system may occur as a result.
Only remove or replace modules when the power is disconnected.
Always comply with the required standards and safety guidelines when configuring a
system.
Mixing up ET-Connection1 and ET-Connection2
When connecting the modules, always ensure that they are properly connected.
If you mix up the lines for ET-Connection1 and ET-Connection2 when connecting the
modules, this can lead to undefined states in your system.
Behavior of ET-Connection
During ongoing operation, a module replacement may be necessary, e.g. because the
module is defective. If an I/O module fails in an ET-Connection line, the line remains active up
to the failed I/O module. After replacing the I/O module, the ET‑Connection line starts up by
itself.
122
WARNING
WARNING
Distributed I/O system
System Manual, 12/2023, A5E31861578-AL
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