Configuration notes:
Open communication via Industrial Ethernet is supported by CPU 31x-2PN/DP, CPU 319-3PN/DP and CPU 41x-3PN/DP via the integrated Industrial Ethernet interface. Some S7-400 CPUs also support open IE communication via CPs. 

In the following lists on communication via Industrial Ethernet

1. with the S7 300
   
       IE_Kommunikation_S7300.pdf ( 4 KB )
2. with the S7 400
   
       IE_Kommunikation_S7400.pdf ( 4 KB )

you can see which communication services are supported via the open IE communication or via configured Send/Receive connections, depending on the hardware components used.

With open IE communication there is no need for any configuration in NetPro. Communication in this case runs via so-called T blocks. You will find these in the Standard Library under Communication Blocks.

Connection parameters:
 

Configured communication connection (via CP)	Open IE communication (with T blocks)
You configure the connections in NetPro. Fig. 01	The connection parameters are stored in a data block. This data block consists of one or more UDT65s. Fig. 02
Note: The CP (and thus also the connections) can also be parameterized with FB55 "IP_CONFIG" during runtime. More information on this is available in Entry ID: 21988384.	Note: Information on the setup of the UDT65 and on the parameterization of the function blocks is available in the manual "System software for S7-300/400 system and standard functions", chapter 23 "Open communication via Industrial Ethernet", in Entry ID: 1214574

Connection setup:
 

Configured communication connection (via CP)	Open Ethernet communication (with T blocks)
The firmware triggers and monitors connection setup.	The connection is set up via function block FB65 "TCON". Once the connection has been set up, it is monitored and maintained automatically by the CPU. More information on parameters and status information is available in the Online Help of STEP 7.

Data exchange:
 

Configured communication connection (via CP)	Open Ethernet communication (with T blocks)
The data is exchanged via the communication blocks FC5 "AG_SEND" and FC6 AG_RECV". These are located in the SIMATIC_NET_CP library.	If data is exchanged via the TCP or ISO-on-TCP protocol, then you call the communication blocks FB63 "TSEND" and FB64 "TRCV" in the S7 program. If data is exchanged via the UDP protocol, then you call the communication blocks FB67 "TUSEND" and FB68 "TURCV".
Note: A sample communication with FC5/FC6 is available in Entry ID 8707570.	Note: The following entries contain sample programs for open communication via Industrial Ethernet using the TCP protocol: 29737950 using the ISO-on-TCP protocol: 29737976 using the UDP protocol: 29738463

Connection clear-down:
 

Configured communication connection (via CP)	Open Ethernet communication (with T blocks)
The firmware clears down the connection automatically.	The connection is cleared down via function block FB66 "TDISCON". More information on parameters and status information is available in the Online Help of STEP 7.