
n
DeviceNet employs a master line/tap line topology with up to 64
network nodes. The maximum distance is either 500m at a rate of
125kbit/s, 250m at a rate of 250kbit/s or 100m at a rate of 500kbit/
s.
n
The length of the tap lines can be up to 6m while the total length
of all tap lines depends on the transfer rate.
n
Network nodes can be removed from or inserted into the network
without interruption of the network operation. New and failed sta-
tions are detected automatically.
n
DeviceNet operates according to the Carrier-Sense Multiple
Access (CSMA) principle, i.e. every station on the network may
access the bus when it is not occupied (random access).
n
The exchange of messages is message orientated and not station
orientated. Each message is provided with a unique and priorizing
identifier. At any time only one station is able to occupy the bus
with its messages.
n
The DeviceNet bus access control is subject to non-destructive,
bit-wise arbitration. In this case non-destructive means that the
successful station participating in the arbitration doesn't need to
re-send its message. The most important station is selected auto-
matically when multiple stations access the bus simultaneously. If
a station that is ready to send recognizes that the bus is occupied,
its send request is delayed until the current transfer has been
completed.
n
All stations on the bus must be uniquely identified by means of an
ID address.
n
Every DeviceNet device has addressing facilities.
n
From VIPA there are EDS (Electronic Data Sheet) files for the
DeviceNet coupler available. These files may either be found on
the supplied storage media or at the download area of
www.vipa.com
n
Please install the EDS file you require in your configuration tool.
Details on the installation of the EDS file are available from the
manual supplied with your configuration tool.
4.2 Accessing the System SLIO
In the following you will find the description of accessing I/O area,
parameter data and diagnostics data of the System SLIO via Devi-
ceNet:
Bus access method
Addressing
EDS file:
Overview
VIPA System SLIO IM 053DN
Deployment
Accessing the System SLIO
HB300 | IM | 053-1DN00 | GB | 15-33
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