Operating Modes Of The Cpu; Startup Mode - Siemens SIMATIC S7-1500 System Manual

Commissioning

10.5 Operating modes of the CPU

10.5 Operating modes of the CPU
Introduction
Operating modes describe the states of the CPU. The following operating states are possible
via the mode selector:
● STARTUP
● RUN
● STOP
In these operating modes, the CPU can communicate, for example, via the PROFINET IO
interface (X1).
The status LEDs on the front side of the CPU indicate the current operating mode.
10.5.1

STARTUP mode

Function
Before the CPU starts to execute the cyclic user program, a startup program is executed.
By suitably programming startup OBs, you can specify initialization tags for your cyclic
program in the startup program. That is, you can set up one or several startup OBs in your
program, or none at all.
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Automation system
System Manual, 09/2016, A5E03461182-AD