Siemens SIMATIC ET 200AL System Manual page 51

The figure below shows the maximum configuration with modules of the ET 200AL
distributed I/O system.
Figure 6-1
Reference
You can find additional information on this topic in section Configuration control (option
handling) (Page 51).
Configuration - PROFIBUS maximum configuration
Each of the connections for ET-Connection occupies a slot in the configuration. The slot for
ET-Connection1 is statically defined in the PROFIBUS GSD file. ET-Connection1 is always
permanently installed in slot 1. Always place the topology module for ET-Connection2 on slot
18. You do not need to fill slots in the configuration for ET-Connection1 with dummy
modules.
The fixed slot assignment of ET-Connection1 and ET-Connetion2 offers you the following
advantages:
● You can expand ET-Connection1 and ET-Connection2 without a high workload; for
ET-Connection1 you need to remove the placeholder, the I/O module is placeable (no
placeholders are needed for ET-Connection2)
● You cannot configure more modules on ET-Connection1 or ET-Connection2 than are
allowed.
● Transparency in configuration control
● Simplification of diagnostics alarms and troubleshooting
Distributed I/O system
System Manual, 02/2018, A5E31861578-AF
PROFINET maximum configuration
Configuring
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