Siemens SIMATIC PCS 7 Function Manual page 73

Functionality
FF Link connects PROFIBUS DP and FOUNDATION Fieldbus with one another and decouples
various transmission rates. It is a slave on the PROFIBUS DP and master on the
FOUNDATION Fieldbus. From the point of view of the automation system, the FF Link is a
modular slave. The individual modules of this slave are the field devices that are connected
to the lower-level FF segment.
The FF devices connected to the FF segment are assembled at one PROFIBUS address by
the FF Link .
The FF Link can be connected directly to the PROFIBUS DP interface of data record gateway
capable PLCs for the coupling between PROFIBUS DP and FOUNDATION Fieldbus .
Versions
You can connect one FF segment to the PROFIBUS DP for each FF Link . The following
variants can be realized:
● Connection to a singular PROFIBUS DP
● Connection to a redundant PROFIBUS DP
Physical bus characteristics
● The application protocols for PROFIBUS DP and FOUNDATION Fieldbus are determined
● Depending on the power consumption of the FF devices, up to 31 FF devices can be
Use in hazardous areas
● The intrinsically safe PROFIBUS DP is specified for the type of protection EEx(ib) .
● When the FF Link is built into an enclosure conforming to at least an IP 54 degree of
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02
– Connection via FF Link (1 x IM 153-2 FF, 1 x FDC 157)
– Connection of a redundant FF segment:
Additional information on this topic can be found in the "Configuring FF Link (Page 124)"
section.
– Connection of a singular FOUNDATION Fieldbus via FF Link to a redundant interface
(2 x IM 153-2 FF und 1 x FDC 157)
– Connection of a redundant FF segment:
For additional information, refer to the section titled "Fault-tolerant FOUNDATION
Fieldbus (Page 74)".
according to IEC 61158-2.
– You can set the transmission speed on the PROFIBUS DP . The maximum transmission
rate is 12 Mbps.
– The transmission speed on the FOUNDATION Fieldbus is 31.25 Kbps. The transmission
method is determined by IEC 61158-2 .
connected to the FOUNDATION Fieldbus .
protection, the FF Link can be installed in operating environments up to Ex Zone 2.
Fault-tolerant Solutions in PCS 7
3.3 Solutions for communication
73