Technical data

Table Of Contents
System Status Lists (SSL)
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
33-3
33.2 Structure of a Partial SSL List
Basics
You can read partial lists and partial list extracts using SFC 51 "RDSYSST." You
specify what you want to read using the parameters SSL_ID and INDEX.
Structure
A partial list consists of the following:
A header and
The data records.
Header
The header of a partial list consists of the following:
SSL-ID
Index
Length of a data record of the partial list in bytes
Number of data records contained in the partial list.
Index
With certain partial lists or partial list extracts an object type ID or an object number
must be specified. The index is used for this purpose. If it is not required for the
information, its contents are irrelevant.
Data Records
A data record in a partial list has a specific length. This depends on the information
in the partial list. How the data words in a data record are used also depends on
the particular partial list.