Siemens Simantic ET200SP - Selecting the BaseUnit for I;O modules

Application planning
3.1 Selecting the BaseUnit for I/O modules
Distributed I/O system
36 System Manual, 12/2016, A5E03576849-AG
3.1
Selecting the BaseUnit for I/O modules
3.1.1
Digital, fail-safe, communication, technology or analog modules without
temperature measurement
Selection of a suitable BaseUnit
①
Light-colored BaseUnit: Configuration of a new potential group, electrical isolation from adjacent module on the left.
The first BaseUnit of the ET 200SP is usually a light-colored BaseUnit for feeding the supply voltage L+.
Exception: If you insert an AC I/O module or an AI Energy Meter as the first I/O module, the first BaseUnit in the
ET 200SP configuration can be a dark-colored BaseUnit. The requirement is that you use a CPU or IM 155-6 (as of
V3.0).
Dark-colored BaseUnit: Conduction of the internal power and AUX buses from the adjacent module on the left.
②
AUX terminal: 10 internally bridged terminals for individual use up to 24 V DC/10 A or as protective conductors.
Example: Multiple cable connection for DI 8×24VDC ST
Figure 3-1 Digital, fail-safe, communication, technology or analog modules without temperature measurement