Operating State - Siemens SIMATIC S7-400 Installation Manual

Glossary
O
OB
→ Organization Block
OB Priority
The operating system of the S7-400 CPU differentiates between various priority
classes, for example, cyclic program processing, process interrupt-controlled
program processing. Each priority class is assigned organization blocks (OBs),
where the S7 user can program a reaction. As a standard, the OBs have different
priorities to which they are processed when they occur simultaneously or when
they interrupt each other.

Operating State

The SIMATIC S7 programmable controllers recognize the following operating
states: STOP, STARTUP, RUN.
Operating System of the CPU
The operating system of the CPU organizes all functions and sequences of the
CPU which are not connected to a specific control task.
Organization Block (OB)
Organization blocks form the interface between the operating system of the S7-400
CPU and the user program. The sequence in which the user program should be
processed is laid down in the organization blocks.
P
Parameter
1. Variable of a STEP 7 logic block
2. Variable for setting the reaction of a module (one or more per module).
Parameters can be static or dynamic.
Parameters, Dynamic
In contrast to static parameters, dynamic parameters of modules can be changed
during operation by calling an SFC in the user program, for example, limit values of
an analog signal input module.
Glossary-10
Automation System S7-400 Hardware and Installation
A5E00850741-01