System Description Of The Btl5-T110; Profibus Technology; Overview Of Profibus Dp; Cyclic Process Data - Balluff BTL5-T110 Series Technical Description

BTL5-T110...
Configuration and Profibus Connection –
Transducer Class 3/4
1 System description of the BTL5-T110-... on Profibus
1.1

Profibus technology

PROFIBUS is a manufacturer-neu-
tral, open field bus standard
specified in EN 50170 and
EN 50254. There are 3 variants:
DP, FMS and PA. Balluff
Micropulse transducers support
the DP variant and are designed
for the common transmission rates
up to 12 MBaud.
In addition to manufacturer-
specific functions the devices
support encoder profile Classes 3
and 4.
This device profile can be ordered
from the Profibus user organization
as part number 3.162. There you
can also obtain additional
information about PROFIBUS
(functionality, manufacturers,
products) as well as standards
and profiles:
Profibus-Nutzerorganisation
Haid-und-Neu-Straße 7
76131 Karlsruhe
Tel.: +49 721 / 96 58 590
Fax: +49 721 / 96 58 589
www.profibus.com
1.2

Overview of Profibus DP

Fig. 1-1: DP version history
1.3

Cyclic process data

A controller designated as PROFI-
BUS Master Class 1 controls its
decentral periphery using cyclic
data exchange.
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english
The controller uses an initializing
phase to initialize each peripheral
device and monitors during cyclic
data transmission whether the
peripheral device, called a slave in
PROFIBUS terminology, remains
accessible.
For its part the slave uses a
watchdog to monitor whether the
controller remains active.
In the cyclic sequence the master
sends its output data to the slave
and receives in response the input
data. The PROFIBUS network for
cyclic process data is thus like a
distributed process map of a
controller.
In a PROFIBUS network there must
always be at least one Class 1
master present. Several Class 1
masters may be on the same bus
however. This means they share
the bandwidth, i.e. the cycle time
becomes correspondingly longer. A
slave can only be controlled by a
Class 1 master!
These basic functions for cyclic
process data are called DP-V0.
Protocol expansions DP-V1 and
DP-V2 make it possible to set the
cycle time of the controller to a
fixed value and use special
telegrams to synchronize the cycle
time of the slaves with the PROFI-
BUS cycle.
1.4

Acyclic parameterizing data

It is common in a system that the
parameters for a device need to
be modified on the fly. Here
PROFIBUS provides
communication using acyclic
parameterizing data. A
parameterizing master, which in
PROFIBUS terminology is a Class
2 master, can open a connection
to a slave and exchange data
acyclically. On a networkseveral
Class 2 masters can exist in
addition to the Class 1 master and
exchange data with the same
slave. Each Class 1 master can
also be a Class 2 master at the
same time. An alarm model is also
defined. Each slave has a status
machine for alarms, monitors
incoming and outgoing alarms of
various kinds, and monitors Class
1 master acknowledgements.
These protocol expansions for
acyclic data exchange are referred
to as DP-V1.