Profibus; Transmission Technology; Bus Topology - Siemens SITRANS P DS III Operating Instructions Manual

● managed
● simulated
3.10

PROFIBUS

The Process Fieldbus (PROFIBUS) is an open communications system for automation
technology and is specified in the international standard IEC 61158.
PROFIBUS Process Automation (PROFIBUS PA) is a variant of PROFIBUS Decentral
Peripherals (PROFIBUS DP), which is widely used in process technology.
3.10.1

Transmission technology

The PROFBUS PA has the special transmission technique MBP (Manchester coded Bus
Powered) and therefore satisfies the requirements of process automation and process
engineering requirements.
This transmission technology is defined in the international standard IEC 61158-2.
The PROFIBUS PA is based on the FISCO model (Fieldbus Intrinsically safe Concept) and
can therefore be used in hazardous areas.
3.10.2

Bus topology

The bus topology is mainly able to be selected as desired. Therefore, line, star and tree
structures, and mixed forms are possible. All types of field devices such as transmitters,
actors, analysis devices, etc. can be connected to the PROFIBUS PA.
Advantages include:
● Savings on installation costs
● More extensive diagnostics, leading to increased availability of installation sections
● Automatic management of installation documentation
● Installation optimization on the fly during operation
In an automation system, there are generally multiple PROFIBUS PA lines connected to fast
PROFIBUS DP via coupler units. This is also connected to the process control system.
Both bus systems use the same protocol layer. This makes PROFIBUS PA a
"communications-compatible" extension of the PROFIBUS DP into the field.
SITRANS P DS III/P410 with PROFIBUS PA
Operating Instructions, 02/2016, A5E00053276-08
Description
3.10 PROFIBUS
37