Siemens SIMATIC ET 200S Manual page 147

OP communication
OP communication enables data exchange between operator stations (e.g. OP,
TP) and communications-capable SIMATIC modules. The utility is possible on MPI
and PROFIBUS subnetworks.
OP communication provides functions which are required for operation and
monitoring. These functions are integrated in the operating system of the
SIMATIC S7 modules.
A CPU can maintain several connections to one or more OPs simultaneously.
S7 basic communication
S7 basic communication enables data exchange between S7-CPUs and
communications-capable SIMATIC modules within an S7 station (acknowledged
data exchange). Data is exchanged by means of non-configured S7 connections.
The utility is possible on the MPI subnetwork or in the station of function modules
(FM).
S7 basic communication provides functions which are required for data exchange.
These functions are integrated in the operating system of the IM 151-7 CPU.
The user can use the utility via the "System Function" user interface (SFC).
S7 communication
The IM 151-7 CPU can only be a server in S7 communication. The connection is
always set up by the communication partner. The utility is possible on MPI and
PROFIBUS subnetworks.
The utilities are processed by the operating system without an explicit user
interface.
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04
Functions of the IM 151-7 CPU
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