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5. Overview
18 Festo P.BE-CMMS-FHPP-DN-SW-EN en 1103a
5. Overview
5.1 Overview of DeviceNet
DeviceNet is a machine-orientated network which enables connections between simple
industrial devices (sensors, actuators) and higher-order devices (controllers). DeviceNet is
based on the CIP protocol (Common Industrial Protocol) and shares all common aspects of
CIP with adaptions which enable the frame size of messages to be adapted to that of
DeviceNet. Fig. 5.1 DeviceNet network shows an exanple of a typical DeviceNet network.
Fig. 5.1 DeviceNet network
DeviceNet offers:
•
An economic solution for networks at the device level
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Access to information in devices at a lower level
•
Possibility for master/slave and peer-to-peer
DeviceNet pursues two main aims:
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Transporting control-orientated information which is in connection with devices of the
lower level (I/O connection).
•
Transporting further information which is indirectly connected with the closed-loop
system such as configuration parameters (Explicit Messaging Connection).
5.2 I/O connection
Some types of I/O connection are defined by DeviceNet. At present only Poll Command /
Response Message with 16 bytes input data and 16 bytes output data are supported. This
means that the master periodically sends 16 bytes of data to the slave and the slave also
replies with 16 bytes.