Lenze · I/O system 1000 · Reference Manual · DMS 5.0 EN · 09/2016 · TD17 404
8 DeviceNet communication
8.1 About DeviceNet
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8 DeviceNet communication
8.1 About DeviceNet
DeviceNet is an open device net standard that satisfies the user profile for industrial real-time
system applications. The DeviceNet protocol has an open specification that is the property of and
administered by the independent vendor organization "Open DeviceNet Vendor Association" ODVA.
This is where standardised device profiles are created to provide compatibility and exchangeability
on logical level for simple devices of the same type.
In contrast to the classical source–destination model, DeviceNet uses a modern producer/consumer
model that requires data packets with identifier fields for the identification of the data. This
approach caters for multiple priority levels, more efficient transfers of I/O data and multiple
consumers for the data.
A device that has data to send produces the data on the network together with an identifier. All
devices requiring data listen for messages. When devices recognize a suitable identifier, they act
and consume the respective data.
DeviceNet carries two types of messages:
• I/O messages
Messages that are subject to critical timing constraints and contain data for control purposes
that can be exchanged by means of single or multiple connections and that employ identifiers
with a high priority.
• Explicit messages
These are used to establish multi-purpose point-to-point communication paths between two
devices, which are used for the configuration of network couplers and for diagnostic purposes.
These functions usually employ identifiers of a low priority.
Messages that are longer than 8 bytes are subject to the fragmentation service. A set of rules for
master/slave, peer-to-peer- and multi-master connections is also available.
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