Usable Networks; Usable Communication Services - Siemens SIMATIC S7-400H System Manual

Resource requirements of fault-tolerant S7 connections
The fault-tolerant CPU supports the operation of 62/30/14 (see the technical specifications)
fault-tolerant S7 connections. On the CP each subconnection requires a connection resource.
NOTICE
If you have configured several fault-tolerant S7 connections for a fault-tolerant station,
establishing them may take a considerable time. If the configured maximum communication
delay is set too short, link-up and updating is aborted and the redundant system state is no
longer reached (see section Time monitoring (Page 106)).
11.3

Usable networks

Your choice of the physical transmission medium depends on the required expansion,
targeted fault tolerance and transmission rate. The following bus systems are used for
communication with fault-tolerant systems:
● Industrial Ethernet (fiber-optic cable, triaxial or twisted-pair copper cable)
● PROFIBUS (fiber-optic cable or copper cable)
For further information on suitable networks, refer to the "
Industrial Twisted Pair Networks
"
11.4

Usable communication services

The following services can be used:
● S7 communication using fault-tolerant S7 connections via PROFIBUS and Industrial
● S7 communications using S7 connections via MPI, PROFIBUS and Industrial Ethernet
● Standard communication (e.g. FMS) via PROFIBUS
● S5-compatible communication (e.g. SEND and RECEIVE blocks) via PROFIBUS and
The following are not supported:
● S7 basic communication
● Global data communication
● Open communication via Industrial Ethernet
S7-400H
System Manual, 09/2007, A5E00267695-03
Ethernet Fault-tolerant S7 connections are possible only between SIMATIC S7 stations.
Fault-tolerant communication is possible over Industrial Ethernet only with the ISO
protocol.
Industrial Ethernet
PROFIBUS Networks
" and "
Communication
11.3 Usable networks
Communication with SIMATIC
" manuals.
",
161