Kübler Group 3 Product Description
HB Profibus Interface - R67068.0002 - 01 EN - 9
3.3 PROFIBUS Interface Description
The main task of PROFIBUSDP is the cyclic transmission of process data from the control sys-
tem to the peripheral devices and vice versa. The access procedure uses the master-slave prin-
ciple. In polling operation, the master serves the slave devices assigned to it one after the other.
Data exchange is initiated by a query telegram and ended by an acknowledgment telegram
from the addressed slave. Thus every slave becomes active only upon request from the master.
This prevents simultaneous bus access. The hybrid access method of PROFIBUS allows com-
bined operation of several bus masters or mixed operation of PROFIBUSDP and
PROFIBUSFMS within a bus section.
Prerequisite for this is, however, the proper configuration of the bus system and the unambigu-
ous allocation of the slave devices to the masters. PROFIBUSDP distinguishes two master
types:
Class 1 master (DPM1): generally the automation system (PLC). It is in charge of the cyclic
transmission of the operating data and makes the user data available. The Class 1 master can
be addressed by a class 2 master that uses determined functions such as e. g. read or write
services via an initiate service.
Class 2 master (DPM2): the engineering tool that exclusively performs acyclic data transmis-
sion. The communication on the bus is based on whether a class 1 master or a class 2 master
initiates the communication.
NOTICE
Direct access to the slaves is not allowed.
The functions are limited to slave support services such as e.g. the
readout of diagnostic information. Therefore, a class 2 master is un-
derstood as a programming or diagnostic device.
3.4 Supported Standards and Protocols
Class 1
Resolution 16 bits
(typ. singleturn)
Class 2
Resolution 32 bits
(typ. multiturn)
In/output consistent The encoder uses
1 input word and
1 output word, which are re-
spectively
consistently transmitted via
the bus.
The encoder uses
2 input words and
2 output words, which are re-
spectively consistently transmit-
ted via
the bus.
Input consistent The encoder uses
1 input word, which is consist-
ently transmitted via the bus.
The encoder uses
2 input words, which are respect-
ively consistently transmitted via
the bus.
For commissioning, the device requires the corresponding GSD data:
To Next Page
Loading...