Siemens NCM S7 Manual De Usuario

25

SIMATIC NET NCM S7 for Industrial Ethernet
Release 6/2003

C79000–G8976–C129–07

S7 communication via Industrial Ethernet allows program-controlled
communication using communication SFBs/FBs via configured S7 connections.
Per job, up to 64 Kbytes of user data can be transmitted.

The Ethernet CP acts as an “S7 communication relay” by passing on the S7
functions via Industrial Ethernet (see /8/). Depending on the configuration of the
Ethernet CP, data transfer is on the basis of the ISO transport or the ISO-on-TCP
protocol (TCP/IP with RFC 1006).

From the perspective of the user, S7 communication is identical over PROFIBUS
and Industrial Ethernet. 

Two situations can occur depending on device type and plant configuration:

S

S7 connections can be operated between the following nodes with the entire
functionality of S7 communication:

– between S7 stations S7-300 and S7-400;

– between S7 stations and PC/PG stations with an Ethernet CP.

PC/PG with Ethernet CP

S7 – 400

S7 – 300

M7

* only TCP/IP

S7 – 300 / 400

Figure 1-3

Nodes Communicating on S7 Connections over Industrial Ethernet