Siemens SIMATIC NET S7-400 Manual page 14

Application and functions
1.3 Network topology with redundancy (PRP)
A PRP network can be set up both with end devices with PRP capability as well as with
standard components. The following devices can be used:
● End devices with PRP capability (Double Attached Nodes PRP, Double Attached Node
implementing PRP, DANP), for example:
– CP 443-1 RNA
– PC with SOFTNET-IE RNA
– SIPROTEC protective devices with PRP capability
● Standard components (Singly Attached Nodes, SAN)
Standard components without PRP functionality, for example, can be connected to a PRP
network via SCALANCE X-200RNA or RuggedCom RS950G.
SANs can, however, also be connected to a PRP network without supporting the PRP
functionality.
All devices that are intended to use the PRP function in redundant networks must be able to
process frames with length of up to 1532 bytes (oversize frames). If this function is not
supported, data may be lost.
Example of a configuration for a PRP network
The following figure shows the options for connecting devices in a network topology in which
the Parallel Redundancy Protocol (PRP) is used.
Figure 1-2
14
Example of the configuration of a network topology with PRP
CP 443-1 RNA
Manual, 03/2019, C79000-G8976-C299-04