BECKHOFF BC3100 - Manual (Page 21)

PROFIBUS-DP basics
BC3100 21
devices from a variety of manufacturers. The PNO archives this information
for all manufacturers and will supply information on request about
manufacturers’ device master files.
A PROFIBUS master configuration program reads the DMF data and
transfers the appropriate settings to the master. You will find a description
of this in the relevant software manual supplied by the manufacturer of
your master.
Type file (200) The widespread and user-friendly master interfaces for a PLC include the
IM308-C from Siemens. A COMProfibus software under Windows is
available for configuration of the master. During configuration of this master
interface for the Profibus, the features of the slave devices are documented
by the manufacturers in the form of a type file and are made available to
users as a file. The contents and coding of this type file are Siemens-
specific and are supported by Beckhoff, as well as by other manufacturers.
It enables convenient configuration of any chosen DP slaves with a PC
under the user interface of Windows 3.1 and subsequent Windows
versions. GSD files, type files and bitmaps are available for the Beckhoff
bus couplers or bus terminal controllers.
The GSD or type file can be downloaded from the mailbox 0 52 46 / 96 3 -
45 5, AREA 15, or via the Internet (www.beckhoff.com or ftp.beckhoff.com)
or can be ordered on a diskette.
Diagnostic functions The extensive diagnostic functions of PROFIBUS DP make it possible to
localize errors rapidly. The diagnostic messages are transferred via the bus
and collated by the master. They are subdivided into three levels:
Diagnostic type
Station-
related
Messages dealing with the general operating condition of
a subscriber, such as overheating or low voltage
Module-
related
These messages indicate a diagnostic message is
pending for a subscriber within a particular I/O sub-area
(e.g. 8-bit output module)
Channel-
related
This locates the cause of the error in an individual input/
output bit (channel), such as: short circuit on output 2
The bus couplers and bus terminal controller support the diagnostic
functions of the PROFIBUS DP. The manner in which the control unit
evaluates the diagnostic data depends on what support is given by the
master. Please refer to the device manual of your master units to see how
to handle the diagnostics. (Note for ET200U experts: the diagnostics is
device-specific, as for the ET200U; a module in the bus terminal enables
you to evaluate the diagnostics for a specific station and track it right down
to an individual channel in the bus terminal.)
Sync and Freeze Mode In addition to the subscriber-related user data traffic, which DPM1 deals
with automatically, the DP master can also send control commands to an
individual DP slave, to a group, or to all of the slaves simultaneously; these
control commands are transferred as multicast functions. You can use
such control commands to impose the operating modes Sync and Freeze
to synchronize the DP slaves. This facility provides for an event-driven
synchronization of the slaves. They enter Sync mode when they receive a
Sync control command from their appointed DP master. In this operating
mode, the outputs from all the DP slaves are frozen in their current state. If
user data is subsequently transferred, the output data is stored at the DP
slaves, although the output status values remain unchanged. When the
next Sync control command is received from the master, the stored output