Open Communication Via Industrial Ethernet - Siemens SIMATIC S7-400H System Manual

14.1.9

Open Communication Via Industrial Ethernet

Availability
S7-400H CPUs with firmware version 6.0 support "open communication over Industrial
Ethernet" (in short: open IE communication). The CPUs must also be configured accordingly
with this or a higher firmware version.
Functionality
The following services are available for open IE communication:
● Connection-oriented protocols:
● Connectionless protocols:
S7-400H
System Manual, 03/2012, A5E00267695-11
Prior to data transmission connection-oriented protocols establish a logical connection to
the communication partner and close this again, if necessary, after transmission is
completed. Connection-oriented protocols are used when security is especially important
in data transmission. A physical cable can generally accommodate several logical
connections. The maximum job length is 32 KB.
The following connection-oriented protocols are supported for the FBs for open IE
communication:
– TCP to RFC 793
– ISO on TCP according to RFC 1006
Note
ISOonTCP
For data communication with third-party systems via RFC1006, the connection partner
must adhere to the maximum TPDU size (TPDU = Transfer Protocol Data Unit)
negotiated in the ISOonTCP connection establishment.
Connectionless protocols operate without a logical connection. There is also no
establishing or terminating a connection to remote partner. Connectionless protocols
transfer the data unacknowledged and thus unsecured to the remote partner. The
maximum message frame length is 1472 bytes.
The following connectionless protocols are supported for the FBs for open
communication by means of Industrial Ethernet:
– UDP according to RFC 768
The single-cast and broadcast modes are supported.
Communication
14.1 Communication services
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