Siemens SIMATIC ET 200AL - Protocols for Open User Communication

Open User Communication
6.2 Protocols for Open User Communication
Communication
Function Manual, 12/2017, A5E03735815-AF
67
6.2
Protocols for Open User Communication
Protocols for Open User Communication
The following protocols are available for open communication:
Table 6- 1 Transport protocols for open communication
Transport protocol
Via interface
TCP according to RFC 793
PROFINET/Industrial Ethernet
ISO-on-TCP
according to RFC 1006 (Class 4) PROFINET/Industrial Ethernet
ISO according to ISO/IEC 8073
Industrial Ethernet (only CP 1543-1)
UDP
according to RFC 768 PROFINET/Industrial Ethernet
FDL
PROFIBUS
Table 6- 2 Application protocols for open communication
Application protocol
Used transport protocol
Modbus TCP
TCP according to RFC 793
E-mail
TCP according to RFC 793
FTP
TCP according to RFC 793
TCP, ISO-on-TCP, ISO, UDP
Prior to data transfer, these protocols (except UDP) establish a transport connection to the
communications partner. Connection-oriented protocols are used when potential loss of data
needs to be avoided.
The following is possible with UDP:
● Unicast to one device or broadcast to all devices on PROFINET via the PROFINET
interface of the CPU or the Industrial Ethernet interface of the CP 1543-1
● Multicast to all recipients of a multicast group via the PROFINET interface of the CPU* or
the PROFINET / Industrial Ethernet interface of the CP 1543-1
* As of firmware version V2.0, the PROFINET interface of the CPU supports a maximum of 5
multicast groups
Maximum user data lengths UDP: Which maximum user data length is supported for the
UPD is described in the technical specifications in the respective manuals.