Op Communication; S7 Communication - Siemens SIMATIC S7-400H System Manual

14.1.3

OP communication

Properties
OP communication is used to exchange data between HMI stations, such as WinCC, OP, TP
and SIMATIC modules which are capable of communication. This service is available for
MPI, PROFIBUS and Industrial Ethernet subnets.
You can use the OP communication for operator control, monitoring and alarms. These
functions are integrated in the operating system of SIMATIC S7 modules. A CPU can
maintain several simultaneous connections to one or several OPs.
14.1.4

S7 communication

Properties
A CPU can always act as a server or client in S7 Communication. A connection is configured
permanently. The following connections are possible:
● One-sided configured connections (for PUT/GET only)
● Two-side configured connections (for USEND, URCV, BSEND, BRCV, PUT, GET)
You can use S7 communication via integral interfaces (MPI/DP, PROFIBUS-DP,
PROFINET) and, if necessary, via additional communication processors (CP443-1 for
Industrial Ethernet, CP443-5 for PROFIBUS).
The S7-400 features integrated S7 communication services that allow the user program in
the controller to initiate reading and writing of data. The S7 communication functions are
called via SFBs in the user program. These functions are independent of the specific
network, allowing you to program S7 communication over PROFINET, Industrial Ethernet,
PROFIBUS, or MPI.
S7-400H
System Manual, 03/2012, A5E00267695-11
Communication
14.1 Communication services
215