Technical data

11.1 Basics of SINEC L2-DP
SINEC L2-DP is the Siemens implementation of the DIN E19245 Part 3
PROFIBUS-DP.
The L2-DP protocol uses the functions specified in DIN 19245 Part 1 for
layers 1 and 2, and supplements these for the special requirements of
distributed I/Os.
The data exchange in a pure SINEC L2-DP bus system is characterized by
the master- (active station on the bus) slave (passive station on the bus)
relationship. The main purpose of such a SINEC L2-DP bus system is fast
data exchange between the master (PLC) and the distributed slave stations
(for example, I/Os of the ET200U station).
Because the L2-DP protocol is based on Part 1 of the PROFIBUS standard
and the hybrid bus access method it specifies, it also possible to operate
MASTER - MASTER communication in addition to the L2-DP MASTER
-SLAVE communication.
With SINEC L2-DP/PROFIBUS-DP the following configurations are possible:
➣
Communication function of the DP MASTER class 1
The class 1 MASTER polls the slaves assigned to it cyclically and
handles the configured data exchange using its requester and
responder functions.
➣
Communication function of the DP MASTERS, class 2
In SINEC L2-DP/PROFIBUS, a programming, diagnostic or
management device used for diagnostic and service functions is known
as a class 2 MASTER.
Distributed I/Os (DP) B89060/02
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