Eaton PowerXL Series, Руководство по связи

Страница: 112 / 256

88
PROFIBUS-DP External Communication Cards
POWERXL SERIES VFD MN040010EN—June 2018 www.eaton.com
Figure 41. PROFIdrive
The PROFIdrive base model describes an automation system
in terms of a number of devices and their interrelationships
(application interfaces, parameter access). The base model
distinguishes between following device classes.
Communication Services —Two communication services
are defined in the PROFIdrive profile; namely, cyclic data
exchange and acyclic data exchange.
Cyclic data exchange via a cyclic data channel
Motion control system need cyclically updated data during
operation for open and closed loop control purposes. This
data must be sent to the drive units in the form of set
points or transmitted from the drive units in the form of
actual values, via the communication systems.
Acyclic data exchange via an acyclic data channel
In addition to cyclic data exchange, there is an acyclic
parameter channel for exchanging parameters between
control/supervisor and drive units. Access to this data is
not time critical.
PROFIBUS overview
PROFIBUS is a vendor independent, open fieldbus
standard for a wide range of applications in manufacturing,
process and building automation. Vendor independence
and openness are guaranteed by the PROFIBUS standard
EN 50 170. With PROFIBUS, devices of different
manufactures can communicate without special interfaces
adjustment. PROFIBUS can be used for both high-speed
time critical data transmission and extensive complex
communication tasks.
PROFIBUS-DP —Optimized for high speed and inexpensive
hookup, this PROFIBUS version is designed especially for
communication between automation and control systems
and distributed I/O at the device level. PROFIBUS-DP can
be used to replace parallel signal transmission with 24V
or 0 to 20 mA.
The PROFIBUS Family—PROFIBUS specifies the technical
and functional characteristics of a serial fieldbus system
with decentralized digital controllers can be networked
together from the field level to the cell level. PROFIBUS
distinguishes between master and slave devices.
Master Devices —Determines the data communication on
the bus. A master can send messages without an external
request when it holds access rights (the token). Master are
also called “active stations” in the PROFIBUS protocol.
Slave Devices are peripheral devices. Typical devices
include input/output devices, valves, drives and measuring
transmitters. They do not have bus access rights and
they can only acknowledge received messages or send
messages to the master when requested to do so. Slaves
are also called ‘passive stations”.
Profiles —The PROFIBUS-DP protocol defines how user
data to be transmitted between stations over the bus. User
data are not evaluated by the PROFIBUS transmission
protocol. The meaning is specified in the profiles. In
addition, the profiles specify how PROFIBUS-DP is to be
used in the drives PROFIBUS Fieldbus board.
Leading manufacturers of drive technology have jointly
defined the PROFIdrive profile. The profile specifies how
the drives are to be parameterized and how the set points
and actual values are to be transmitted. This enables drives
from different vendors to be exchanged. The profile contains
necessary specifications for speed control and positioning.
It specifies the basic drive functions while leaving sufficient
freedom for application-specific expansions and further
developments. The profile describes the mapping of the
application functions for DP.
PROFIdrive consists of a general part and a bus specific
part. The following properties are defined in the general part.
•
Base Model
•
Parameter model
•
Application Model