Cyclic and Acyclic Services

Overview

In general, the data is exchanged through cyclic service and acyclic services. The application profiles that are supported under cyclic services are:

• Manufacturer independent data

• Manufacturer specific data

The fixed set and defined use of manufacturer independent data enables the replacement of a module from the vendor A and by a module from the vendor B.

DP-V0 Services

The DP-V0 services are used for:

• PROFIBUS DP configuration

• Cyclic input and output (I/O) data exchange, according to a selected data module

• Device and communication diagnostics

DP-V1 Read and Write Services

The DP-V1 read and write services enable the access to the acyclic data sets.

PKW Feature

To make this data accessible also for DP-V0 clients, a special feature called Periodically Kept in acyclic Words (PKW), is implemented. In cyclically exchanged data, there are encapsulated request and response frames. They provide access to TeSys Tera systems internal registers.