Performance data and behavior in operation
5.5 Characteristics of S7 communication
CP 342-5 / CP 342-5 FO
28
Manual, 10/2011, C79000-G8976-C146-09
Time response on FDL connections
Refer to the following table for transmission rates with FDL connections dependent on the
following parameters:
●
Frame length (number of bytes)
●
CPU type
The values were measured while sending or receiving successively (at a transmission rate of
1.5 Mbps; bus profile standard; 9 nodes).
Table 5- 1
Number of FDL frames per second for CPU 317
Frame length
Number of FDL frames per second
8 bytes
140 / s
128 bytes
138 / s
240 bytes
135 / s
5.5
Characteristics of S7 communication
General characteristic data
The following information is important when operating S7 connections:
Characteristic
Explanation / values
Number of operable S7 connections
16 maximum
S7 connections configured at one end / both
ends; including PG and TD/OP connections
Dependencies and restrictions relating to the number of S7 connections
Depending on the configuration and modes, remember the following:
●
The actual possible number of S7 connections that can be operated depends on the type
of CPU being used. Further restrictions result from multiprotocol mode; note the
information in the section Parallel use of communications services (multiprotocol mode)
(Page 30).
●
If the CP is configured as a DP slave, the following restrictions apply:
–
S7 connections cannot be operated;
–
OP multiplex mode is not possible.
