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5.3 Profibus DP protocol
Data format
The setpoints and readings are transmitted in the IEEE float format (IEEE 754, 32
bits) or the Siemens float format.
The transmission always begins at the same time as the MSB..
Guaranteeing Transmission
The transmission between the controller and the control system can be secured in
the controller by TIMEOUT.
The controller expects a telegram from the control system at certain intervals. Both
the interval and the type of controller's reaction
to no telegrams (refer to the chapter on Event Messages in the operating manual)
can be set on the controller via parameters. The setting TIMEOUT = 0 means that
the data flow between the controller and control system is not monitored by the
controller.
Routines
Any routines important for specifying data are described in each section.
Subscriber addresses
Every controller is given a slave address beginning with 0 in ascending order. The
highest address it is possible to set is labeled MAXSLAVE in the following text.
You can set the address by dialog on the controller and MAXSLAVE has the value
126.
5.3.1
Data segments
We distinguish:
The writing range with
and the reading range with
Blocks of four bytes each can be unambiguously addressed with a two-byte
identifier (ID; refer to the tables on "Available Data").
72
n
control information,
n
predetermination values in the IEEE format,
n
Setpoints in the LONG integer format
n
Texts from the master to the controller (not with DISOMAT Satus)
n
status information
n
Readings in the IEEE format
n
Readings in the LONG integer format
n
The controller's texts (not with DISOMAT Satus)
BV-H2359GB/0902
DISOMAT Opus, Satus, Tersus, Data Communication
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