Performance Data; Configuration Limits - Hardware - Siemens SIMATIC S7-400 Operating Instructions Manual

Note the following restrictions:
● The CP does not support H communication.
● The CP does not support redundancy mechanisms.
Operating the CP in an H system
Each of the two redundant H CPUs has a CP plugged in which is assigned in each case to
one of the two CPUs in the configuration ("General" tab).
Below the cases will be examined where the two CPs function as OPC UA server or as OPC
UA client in the H station.
CPs as servers in an H station
Each CP as OPC UA server only allows a client access to the data of its assigned CPU.
So that the client can handle the failure of one of the two H CPUs, the client must access the
data of both CPs of the station (OPC UA server). A comparison of the redundant process
data by the client must be made by the client application.
CPs as clients in an H station
Both CPs as OPC UA clients access the data of a server.
Which data read from the currently active H CPU (redundancy master) is used must be
implemented within the S7 user program via the UDT "UASessionConnectInfo".
1.6

Performance data

1.6.1

Configuration limits - hardware

Equipment of the S7 stations
Number of CPs per station
In each S7-400 station, up to 14 CPs can be plugged in and configured, of which a maximum
of one CP 443-1 OPC UA.
Number of supported CPUs per rack
Depending on the system setup, several CPUs can be plugged in in the rack.
For OPC UA communication the CP 443-1 OPC UA can, however, only access the data
areas of a single CPU. You assign the CPU to the CP in the configuration, see section
"Addresses" tab (Page 45).
CP 443-1 OPC UA
Operating Instructions, 01/2017, C79000-G8976-C427-02
Application and functions
1.6 Performance data
15