WL Circuit Breakers - Siemens

Data Transmission via DPV1
WL Circuit Breaker
Pre-Assignment of the Three Basic Types
Once a basic type has been selected with
the PROFIBUS-DP master configuration tool,
the configured slave is requested by the
master to communicate in this basic type
at start-up.
Each WL circuit breaker can be configured
individually with a different basic type.
Selecting the basic type first defines the
quantity of data and, therefore, the length
of the message.
The key circuit breaker data can now be
transmitted without the need to make any
additional settings. The status of the circuit
breaker is the same for all three basic types.
This information field is 2 bytes in size and
will be explained in more detail later. In
line with the status field, the basic types
comprise between 4 and 14 data blocks,
which are all pre-assigned.
The format for all the pre-assigned
measured values is a one-word integer.
This must be interpreted in Motorola
format, which can be regarded as the
“standard” for PROFIBUS-DP.
Basic Type 1
In line with the 2-byte status information,
basic type 1 comprises four data blocks.
These are pre-assigned in such a way that
they are designed for use with a WL
circuit breaker without the Metering
Function. The most important phase
currents are transmitted here. This preassignment
can be changed if necessary.
The content can be reconfigured or the
default values changed using the BDA. or
Profibus DP configuration software (e.g.
Switch ES Power).
3/11
Basic Type 2
Basic type 2 comprises 8 data blocks, which
are pre-assigned for a WL breaker with the
Metering Function. Not all of the voltages are
transmitted in full, only the main values are
transmitted, which is sufficient in most cases.
Basic Type 3
With basic type 3, the 14 data blocks are
assigned measured values. This basic type
has also been pre-assigned in such a way that
it is only practical to use it with the WL with
a metering function if the pre-assigned
values are not modified. As described
above, however, basic type 3 can be
selected and the pre-assigned measured
values that are not available (e.g. phaseto-phase
voltage) can be replaced by
maintenance or parameter data as required.
The pre-assigned data can be replaced with
any information that is no more than 2
bytes long. All the other values are ”cast,”
or, truncated and adapted so that only the
2 least significant bytes are transmitted.
Definition of the Property Byte
Value Data point is ...
0x �0 Read and writable
Least significant
byte
0x �1
0x �2
Read only, but can be reset (e.g. maintenance)
Read only, writable in factory only
0x �3 Read only
0x0� Not available
Most significant
byte
0x4�
0x5�
Available, but option deactivated
Available, but option deactivated and outside the area
0x6� Available and activated, but outside the area
0x7� Available, activated, within the area, and valid
Table
3-7
The property byte describes the properties of the accompanying data point.
Property Byte (PB)
In each of the basic types, the assigned data
blocks are followed by the accompanying
property bytes. Each data block has its own
property byte.
The property byte provides additional
information on the accompanying data
block. Although it does not have to be
analyzed, it may contain important
information for the application. A property
byte is also available for each data point in
the DPV1 data records. If the content of one
or more data blocks in the cyclic message
is replaced, the property byte is adapted
automatically. Property bytes can be used
to determine whether a value is available.
WL PROFIBUS/MODBUS Communication and Electronic Accessories