1.5.3 DeviceNet
DeviceNet is a communications link that connects industrial devices to a network. It is based on the broadcast-oriented, communications protocol CAN
(Controller Area Network).
The CAN protocol was originally developed for the European automotive market to be used in exchange for expensive wire harnesses in automobiles. As
a result, the CAN protocol offers fast response and high reliability for demanding applications like ABS brakes and air bags.
Danfoss concept offers the cost optimal DeviceNet solution
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Cyclic I/O communication
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Acyclic communication – “explicit messaging”
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Unconnected Messages Manager (UCMM) messages are supported
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Integrated solution
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Electronic Data sheet (EDS)-files secures easy configuring
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Provides fieldbus voltage supply
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Fulfilment of DeviceNet AC/DC motor profile
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Protocol defined in accordance with the Open DeviceNet Vendor Association (ODVA)
1.5.4 AS-interface
AS-interface (AS-i) is a cost-efficient alternative to conventional cabling at the lowest level of the automation hierarchy. The network can link into a higher-
level fieldbus like Profibus for low-cost remote I/O. Known by its yellow cable; AS-I has grown an “open” technology supported by more than 100 vendors
worldwide. Enhancements through time have broadened its field of applications and AS-interface is today proven in hundreds of thousands of products
and applications spanning the automation spectrum.
1.5.5 Modbus
The frequency converter communicates in Modbus RTU format over an EIA-485 (formerly RS-485) network. Modbus RTU allows access to the frequency
converter's Control Word and Bus Reference.
The Control Word allows the Modbus master to control several important functions of the frequency converter:
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Start
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Stop the frequency converter in several ways:
Coast stop
Quick stop
DC Brake stop
Normal (ramp) stop
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Reset after a fault trip
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Run at a variety of preset speeds
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Run in reverse
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Change the active setup
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Control the frequency converter's two built-in relays
The Bus Reference is commonly used for speed control.
It is also possible to access the parameters, read their values, and, where possible, write values to them. This permits a range of control possibilities,
including controlling the frequency converter's setpoint when its internal PID controller is used.
1 The Decentral Concept
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Decentral FCD 300 Design Guide
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MG.90.S1.02 - VLT
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is a registered Danfoss trademark
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