Description
3.6 PROFIBUS PA
SIPART PS2 with PROFIBUS communication
32
Operating Instructions, 09/2007, A5E00127926-07
3.6
PROFIBUS PA
3.6.1
Overview
The Process Field Bus (PROFIBUS) is an open communication system for automation
technology and is specified in the European standard EN 50170.
PROFIBUS Process Automation (PROFIBUS PA) is a variant of PROFIBUS Decentral
Peripherals (PROFIBUS DP), which is widely used in process technology.
3.6.2
Transmission technology
PROFIBUS PA uses a special transmission technology, enabling it to fulfill the requirements
of process automation and process technology. This transmission technology is defined in
the international standard IEC 61158-2. The low transmission rate reduces the power loss in
comparison to PROFIBUS DP, enabling an intrinsically safe technology for use in hazardous
zones with explosive atmospheres.
3.6.3
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, in general, multiple PROFIBUS PA strands connected to
the 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.