Application and functions
1.4 Performance data
CP 443-5 Extended
20
Manual, 11/2018, C79000-G8976-C162-09
1.4.5
Parallel use of communications services (multiprotocol mode)
Performance
Using the various available communications services at the same time affects
communication performance.
To illustrate the relationship between the connection types, the DP mode, and configured
connections, the following values apply to the typical configurations:
Connection type
Number of connections
With the DP configuration
FDL connections
32
No DP mode
32
With DP mode
S7 connections
48
No DP mode
48
With DP mode
FDL and S7 connections
1)
59
No DP mode
54
With DP mode
1) one additional S7 connection can be set up online (for example for routing)
Note
PG or HMI functions or data record routing
If PG or HMI functions or data record routing are used, a suitable number of S7 connections
must be reserved during configuration!
Help provided by STEP 7
The number of connections on PROFIBUS shown in the table above can vary due to other
influencing factors. The STEP 7 configuration tool displays warnings and help messages as
soon as limit values are exceeded.
Scaling of services in the "mixed mode"
The DP delay time is used to scale cyclic DP communication and the other services (FDL
and S7 connections). A DP delay time of 0 seconds guarantees the fastest possible DP
update. By increasing the DP delay time, you create extra time on the CP for handling other
services.
Note
Recommendation for mixed mode - PROFIBUS DP along with communications functions
In mixed mode, a delay should be selected as follows: 1 ms at transmission speeds > 1.5
Mbps
