Siemens SENTRON VL Series System Manual page 136

PROFIBUS data transfer
6.9 Cyclic data traffic
Basic types for cyclic data exchange
Due to the large volume of data provided by the SENTRON circuit breakers, it was
necessary to find a compromise between data volume and performance on PROFIBUS DP.
If a large volume of information is transferred with each data exchange but little of it is used,
this impairs the performance capability on PROFIBUS DP.
For this reason, there are three basic types available for efficient and flexible transfer.
Depending on the application, the most suitable basic type with its associated bus
configuration can be selected at the configuration stage. Configuring is carried out with a
PROFIBUS DP configuration tool such as COM PROFIBUS or HW Config of the
SIMATIC S7. The basic types are already pre-assigned and offer a good method of fast
commissioning without additional configuring/parameterizing.
It is possible to assemble a user-defined configuration within a basic type with the help of
Switch ES Power, for example.
Note
Data that is not constantly required can be additionally transferred via DPV1.
Pre-assignment of the three basic types
After selection of a basic type using the configuration tool of the PROFIBUS DP master, this
configured slave is prompted at the start by the master to communicate in the basic type set.
Each individual SENTRON circuit breaker can be configured with another basic type.
The selection of the basic type defines first the volume of data and thus the length of the
message frame. Without further settings, it is then possible to transfer the most important
data of the circuit breaker. The status of the circuit breaker is identical in all three basic
types. This information field has a size of 2 bytes. According to the status box, the basic
types consist of 4 to 14 data blocks. These are pre-assigned. Each data block has an
associated property byte.
The format for all pre-assigned measured values is an integer with a length of 1 word. This
must be interpreted as the Motorola format that is a de-facto standard on PROFIBUS DP.
The tables below contain lists of the data blocks of the 3 basic types:
Basic type 1 consists of the binary status information and 4 data blocks. The pre-assignment
of basic type 1 is specially designed for current transmission.
136
3WL/3VL circuit breakers with communication capability - PROFIBUS
System Manual, 03/2011, A5E01051353-02