Technical data

Table Of Contents
Glossary
System Software for S7-300/400 System and Standard Functions - Volume 2/2
Glossary-8
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Logic Block
In SIMATIC S7, a logic block is a block that contains part of the STEP 7 user
program. The other type of block is a data block which contains only data. The
following list shows the types of logic blocks:
Organization block (OB)
Function block (FB)
Function (FC)
System function block (SFB)
System function (SFC)
Message
The report of the occurrence of a event. A message can be output to a suitably
configured display device and contains information such as priority, location, and
time of the message event as well as information about the state transition
(entering the state/leaving the state).
Message Configuration
Message configuration refers to the creation and editing of message and message
templates with their texts and attributes and concerns such messages as block-
related messages, symbol-related messages, and diagnostic messages.
Message Number
A unique number assigned to a message and used to identify it, such as for
acknowledgement.
Module Parameter
Module parameters are values with which the behavior of the module can be set.
Depending on the particular module, some of these parameters can be modified in
the user program.
OB1
The organization block OB1 is the user interface for the system program for cyclic
program processing.