Siemens SIMATIC S7-300 CPU Data: CPU 315-T-2 DP User Manual

Communication with the S7-300
5.3 Communication services on the MPI/DP interface (X1)
5.3 5.3 Communication services on the MPI/DP interface (X1)
5.3.1 Overview of communication services
Selecting the communication service
You need to decide on a communication service, based on functionality requirements. Your
choice of communication service will influence
• the functionality available,
• whether an S7 connection is required or not, and
• the connection timing.
The user interface can vary considerably (SFC, SFB, ...), and is also determined by the
hardware used (SIMATIC CPU, PC, ...).
Overview of communication services
The table below provides an overview of communication services offered by the CPU.
Table 5-3 CPU communication services
Communication service Functionality Time at which the S7
connection is established ...
via
MPI
via
DP
to DP(DRIVE)
PG communication Commissioning, test,
diagnostics
from the PG, starting when the
service is being used
X X -
OP communication Operator control and process
monitoring
from the OP at Power ON X X -
S7-based
communication
Data exchange is programmed at the blocks
(SFC parameters)
X - -
S7 communication Data exchange as server only, communication
link is set up by the
communication partner
X X -
Global data
communication
Cyclic data exchange (for
example, flag bits)
does not require an S7
connection
X - -
Routing PG functions* for example testing,
diagnostics on other
networks also
from the PG, starting when the
service is being used
X X X
* Functions can be routed only to DP(DRIVE), but not on DP(DRIVE)!
S7-300 CPU Data: CPU 315T-2 DP
Manual, 12/2005, A5E00427933-02
5-7

Siemens SIMATIC S7-300 CPU Data: CPU 315-T-2 DP Specifications

General

Brand	Siemens
Model	SIMATIC S7-300 CPU Data: CPU 315-T-2 DP
Category	Control Unit
Language	English