Beckhoff CX8010, Руководство пользователя

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PROFIBUS
CX8030 / CX8031 77 Version: 1.6
Type Description
DP master class 1 (DPM1)
e.g. Beckhoff PC master card FC310x
This involves a central controller that exchanges
information cyclically with the distributed stations
(slaves) in a specified message cycle. Typical
devices include, for instance, programmable logic
controllers (PLCs) or PCs.
DP master class 2 (DPM2) Devices of this type are engineering, project design
or operating devices. They are used for
commissioning, for servicing and diagnosis in order
to configure the connected devices, to evaluate
measured values and parameters and to interrogate
the status of devices.
DP slave
e.g. Beckhoff Bus Coupler IPxxxx-B310
A PROFIBUS DP slave is a peripheral device (I/O,
drive, measuring transducer etc.) that reads input
information and passes output information on to the
peripherals. It is also possible to have devices that
only handle either input or output information. The
quantity of input and output information is device-
dependent, and may not exceed 246 bytes of input
data and 246 bytes of output data.
In single master systems only one master is active on the bus in the operating phase of the bus system.
The PLC controller is the central control element. The distributed slaves are coupled to the PLC controller via
the transmission medium. The shortest bus cycle time is achieved with this system configuration.
In a multi-master mode there is more than one master on the bus. They either form sub-systems that are
independent of one another, each consisting of one DPM1 and the associated slaves, or additional project
design and diagnostic devices. All the DP masters can read the input and output images of the slaves.
Writing the outputs is only possible for one DP master (the one assigned as DPM1 during the project
design). Multi-master systems achieve a medium bus cycle time. In time-critical applications, the increase in
bus cycle time should be observed by adding a diagnostic tool.
Basic device files (GSD)
In PROFIBUS DP, the performance characteristics of devices are documented by the manufacturers and
made available to users in the form of a device data sheet and of a basic device file. The structure, content
and coding of these basic device files (GSD) is standardized. They make it easy to plan a project with any
PROFIBUS DP slaves using project planning devices from a various manufacturers. The PROFIBUS User
Organization (PROFIBUS Nutzer Organization - PNO) archives this information for all manufacturers, and
will provide information about the GSD from any manufacturer on request. The GSD files are read by a
PROFIBUS master configuration software, and appropriate adjustments are transferred to the PROFIBUS
master. Please see the appropriate software manual from the master manufacturer for a description.
The Beckhoff GSD files may be obtained from the internet under www.beckhoff.com .
Diagnostic functions
The extensive diagnostic functions of PROFIBUS DP allow rapid fault localization. Diagnosis of the Beckhoff
Bus Coupler is not activated in the default setting of the type file or the GSD file. The diagnostic messages
are transmitted over the bus and collated by the master.
They are divided into three levels: