Configuring Hardware and Communication Connections STEP 7.pdf

Configuring Connections
12.4 What You Should Know About the Different
Connection Types
Introduction
S7 Connections
The following sections provide a brief overview of the connection types you can
configure with STEP 7. The "Communicating with SIMATIC" manual provides a
more detailed description of the communications possibilities in SIMATIC.
S7 connections offer the following features:
• Can be configured in all S7/M7 devices
• Can be used in all types of subnet (MPI, PROFIBUS, Industrial Ethernet)
• When using the SFBs BSEND/BRCV: secure transfer of data between SIMATIC
S7/M7-400 stations; for example, exchanging data block contents (up to 64
Kbytes)
• Using CPU 317-2 PN/DP as well as CPU 31x and a CP with the FBs
BSEND/BRCV from the SIMATIC_NET_CP library or Standard Library also
allows secure transmission of data to S7-300 and S7-400.
• When using the SFBs USEND/URCV: fast, unsecured transfer of data
independent of the time processing of the communication partner, for example,
for event messages and messages.
• Acknowledgement of data transfer from the communication partner via layer 7
of the ISO reference model
S7 Connections, Redundant
• Properties as for S7 connections; however, restricted to S7 H CPUs as well as
SIMATIC PC stations (such as OPC servers) and not on MPI subnets
• Depending on the network topology, at least two connection paths between the
connection end points are possible with a redundant S7 connection.
Configuring Hardware and Communication Connections with STEP 7
12-4 A5E00706939-01