Application planning
4
4.1
Applications for Compact FF Link
The Compact FF Link is intended for the following applications:
● Single-channel operation on a non-redundant S7-4xxH or on a non-redundant DP master
system
(basic schematic in section "Single-channel connection of the Compact FF Link (Page 21)")
● Operation on a redundant S7-4xxH or on a redundant DP master system
(including FF Link Master redundancy)
(basic schematic in section "Redundant connection of the Compact FF Link (Page 21)")
– Operation with coupler redundancy
– Operation with ring redundancy
4.2
Configuration options
Configuration options
A DP master system can be configured as follows:
● The number of bus links on a DP master system is restricted by:
– the number of bus nodes: maximum of 125 on the DP master system (including Compact
FF Link)
– the number of configurable station addresses
● Each FF device uses an address in the configuration.
● The configuration frame and user data frames of the bus link are both derived from the
frame contents of the lower-level FF devices.
● The maximum length of the frames for I/O data at the PROFIBUS DP end: 244 bytes in
each case
● An FF segment is limited to the size of the process image of the bus link (max. 244 bytes
for I/O data in each case).
– You can distribute the 244 bytes for inputs among the FF devices:
- Digital inputs (2 bytes per value, but max. 40 DI)
- Analog inputs (5 bytes per value, but max. 40 AI)
– You can distribute the 244 bytes for outputs among the FF devices:
- Digital outputs (2 bytes per value, but max. 40 DO)
- Analog outputs (5 bytes per value, but max. 40 AO)
– A maximum of 64 bytes for outputs and 64 bytes for inputs are used for each FF device.
Compact FF Link
Operating Instructions, 03/2015, A5E35651552-AA
17
