Characteristic Data Of S7 Communication; Parallel Use Of Communications Services (Multiprotocol Mode) - Siemens SIMATIC NET S7-300 - PROFIBUS Equipment Manual

Speed of the 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 subscribers).
Table 2- 1
Frame length / CPU type / baud rate
8 bytes
128 bytes
240 bytes
2.4

Characteristic data of S7 communication

General characteristic data
The following characteristic data is important when operating S7 connections:
Characteristic
Number of operable S7 connections
1) The actual possible number of S7 connections that can be operated depends on the type of CPU
2.5

Parallel use of communications services (multiprotocol mode)

Speed
Using the various available communications services at the same time affects the
communication speed:
• The FMS speed can decrease with large configuration limits (16 FMS connections) and
more than 8 S7 connections.
• With cyclic NCM diagnostics, the update time should be set to 3 seconds; otherwise, the
communication speed can decrease.
CP 343-5
Equipment Manual, 05/2023, C79000-G8976-C160-04
Number of FDL frames per second
being used.
2.4 Characteristic data of S7 communication
CPU 314 / 1.5 MBaud
129 / s
130 / s
122 / s
Explanation / values
16 max.
1)
Performance data
13