Siemens SIMATIC PCS 7 Function Manual page 79

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 via FF Link (1 x IM 153-2 FF, 1 x FDC 157)
– Connection of a redundant FF segment:
● Connection to a redundant PROFIBUS DP
– Connection of a singular FOUNDATION Fieldbus via FF Link to a redundant interface
– Connection of a redundant FF segment:
Physical bus characteristics
● The application protocols for PROFIBUS DP and FOUNDATION Fieldbus are determined
according to IEC 61158-2.
– You can set the transmission speed on the PROFIBUS DP . The maximum transmission
– The transmission speed on the FOUNDATION Fieldbus is 31.25 Kbps. The transmission
● Depending on the power consumption of the FF devices, up to 31 FF devices can be
connected to the FOUNDATION Fieldbus .
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
protection, the FF Link can be installed in operating environments up to Ex Zone 2.
Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA
You can find additional information on this in the "Configuring FF Link (Page 140)"
section.
(2 x IM 153-2 FF und 1 x FDC 157)
You can find additional information on this in the section "Fault-tolerant FOUNDATION
Fieldbus (Page 80)".
rate is 12 Mbps.
method is determined by IEC 61158-2 .
Fault-tolerant Solutions in PCS 7
3.3 Solutions for communication
79