Siemens SIMATIC ET 200SP HA Manual page 19

Potential group
A potential group consists of a group of adjacently placed I/O modules within an ET 200SP
HA station that are supplied using a common supply voltage.
A potential group begins with a light terminal block via which the needed supply voltage for all
I/O modules of the potential group is fed. The light-colored terminal block interrupts the self-
assembling voltage buses to the left neighbor
All other I/O modules of this potential group are plugged into dark terminal blocks. I/O modules
on dark terminal blocks take the potentials of self-assembling voltage rails from the left
neighbor.
A potential group ends with the dark terminal block that is followed by a light terminal block or
a server module in the station configuration.
You can find additional information on the configuration of the potential group in the system
manual
Analog Input Module AI 16xI 2-wire HART HA ( 6DL1134-6TH00-0PH1)
Manual, 11/2017, A5E39408968-AB
SIMATIC; Distributed I/O System; ET 200SP HA .
4.3 Explanation of the module/channel parameters
Parameters
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