Siemens SIMATIC ET 200AL - Page 1210

Glossary
PROFINET with STEP 7 V15
Function Manual, 12/2017, A5E03444486-AH
263
Master
Higher-level, active participant in the communication/on a PROFIBUS subnet. It has rights to
access the bus (token), sends data and requests it.
Media redundancy
The so-called
M
edia
R
edundancy
P
rotocol (MRP) enables the configuration of redundant
networks. Redundant transmission links (ring topology) ensure that an alternating
communication path is made available if a transmission link fails. The PROFINET devices
that are a part of this redundant network form an MRP domain.
Micro Memory Card (MMC)
Micro Memory Cards are memory media for CPUs and CPs. Their only difference to the
SIMATIC memory card is the smaller size. S7-1500 and ET 200SP-CPUs use
SIMATIC memory cards.
MPI
The multipoint interface (
M
ulti
P
oint
I
nterface,MPI) represents the programming device
interface of SIMATIC S7. It enables multiple devices (programming devices, text-based
displays, OPs) to be operated simultaneously by one or more CPUs. Each device is
identified by its unique (MPI) address.
MRPD
MRPD (
M
edia
R
edundancy with
P
lanned
D
uplication of Frames) based on IRT and MRP. To
realize media redundancy with short update times, the PROFINET devices participating in
the ring send their data in both directions. The devices receive this data at both ring ports so
that there is no reconfiguration time.
Network
A network consists of one or more interconnected subnets with any number of devices.
Several networks can exist alongside each other.
OB
→ Organization block
OPC
OPC (OLE for Process Control) refers to a standard interface for communication in
automation technology.