S5-115U Manual
2
Technical Description
This chapter describes the design and principle of operation of an S5-115U with accessories.
2.1
Modular Design
The S5-115U consists of various functional units that can be combined to suit the particular pro-
blem.
SIEMENS
The numbered information below briefly describes the most important components of the
S5-115U.
Power Supply Module (PS 951)
The PS 951 power supply module generates the operating voltage for the PLC from the
120 V AC/230 V AC or 24 V DC power system voltages. This module uses a battery or an
external power supply to back up the RAM.
The PS 951 power supply module also performs monitoring and signalling functions.
EWA 4NEB 811 6130-02b
Figure 2-1. The S5-115U (Central Unit)
Technical Description
2-1