WL Circuit Breakers - Siemens

Programming Samples
WL Circuit Breaker
Data Exchange via DPV1
PROFIBUS-DPV1 (DPV1) is an enhancement
of the PROFIBUS-DP protocol. PROFIBUS-DP
and DPV1 devices can be connected to one
line. Being downwards compatible, the
PROFIBUS-DP and DPV1 protocol can run on
the same line. With DPV1, additional data
records with up to 240 bytes of user data
can be transmitted acyclically by means
of user programs, such as STEP7 Switch ES
Power, or WinCC.
In this way, the DPV1 protocol can be used
to transmit parameter, diagnostic, control,
and test data quickly and easily.
One prerequisite here is that a DPV1capable
class 1 master or class 2 master is
available. These can be used to transmit
the above data via an additional channel.
Figure
3-9
WL PROFIBUS/MODBUS Communication and Electronic Accessories
With the class 2 master, a communication
link can even be established to slaves that
have not been configured or parameterized
by this master and are still connected
to a class 1 master. A class 2 master is
particularly suitable for commissioning,
diagnosis, and visualization tasks with a
program such as WinCC, for example.
Special system functions that enable
data records to be sent and received are
available in SIMATIC S7 for enhanced
data transmission via DPV1. The following
example illustrates how a data record is read
and written from the WL breaker. System
functions SFC58 (write) and SFC59 (read)
are used.
The WL diagnostic information is currently in the S7 diagnosis buffer. An incoming
diagnostic message is not present.
SECTION 3
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