Siemens SIMATIC NET S7-300 Manual page 30

1 Communication via Ethernet CPs in S7 Stations
Notes on S7 Communication between PC/PG Station and S7 Station
Applications in a PC/PG station communicate with the S7 station over an OPC
interface or SAPI-S7 interface for operator intervention, monitoring and control.
The S7 stations use the integrated communication SFBs/FBs (client and server
functionality at both ends).
The following general requirements must be met by a PC/PG station for S7
communication:
S The following are installed in the PC/PG:
- an Ethernet CP
- there is an interface for S7 communication installed: SOFTNET S7 for Ind.
Ethernet or software from the SIMATIC NET CD.
S The CPs in the S7 stations are supplied with a MAC/IP address (use the default
MAC address or set an IP address).
S The CPs in the S7 stations are supplied with a MAC/IP address (use the default
MAC address or set an IP address).
To use S7 communication with the SIMATIC S7 PLC from a PC, address the
required CPU module in the SIMATIC S7 PLC that you want to communicate with
in your PC application.
S7 Communication via Routers (one-sided Client and Server Functionality)
It is possible to reach the S7 station from an application (OPC server) of the
PC/PG station that is attached to another subnet. The subnets must be connected
over a router such as the IE/PB Link. An S7 station or a PC connected to both
subnets can also serve as a router.
In this configuration, the S7 station can only be addressed by the PC/PG station as
a communications server on S7 connections configured at one end.
The requirements for the configuration of the PC/PG station are identical to those
for operation in the same subnet (see above); the CP in the PC/PG station must
also have routing capability.
In this situation, configure a one-ended S7 connection to the PC/PG station in the
other subnet for the PC/PG station in STEP 7 NetPro. You can then access data in
the S7 station in your user program using the functions PUT (writing) and GET
(reading).
A -30
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07