FDT – A Brief Introduction
FDT Tools
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ifak system GmbH
CommChannel allows other DTMs an access to the fieldbus
communication. It supports the interface “IFdtCommunication“,
which groups the communication access function. A DataChan-
nel allows other DTMs an access to the data values and is pro-
vided by the device DTM. The values could be the process values
of a field device, which were communicated by cyclic data
exchange.
A device in FDT is managed by its dedicated DeviceDTM. Its
ActiveX based HMI allows the user the access to its parameters
and functions. The DeviceDTM communicates with its device
through a CommChannel and the underlying fieldbus interface.
Lets draw a comparison between the FDT terms DeviceDTM,
CommDTM, CommChannel and the terms in use within the
domain of automation software. A DeviceDTM (and its ActiveX
components) replaces the manufacturer specific field device con-
figuration software and the CommDTM (and its ActiveX compo-
nents) replaces the manufacturer specific fieldbus interface
configuration software. A CommChannel equals the driver
library of a communication interface.
If a DeviceDTM is called and attached to a certain device, this
DeviceDTM instance is associated with a CommChannel. The
device can establish a connection to the device through this Com-
mChannel. Contrary to today’s practice the DeviceDTM can
expect an interface with a manufacturer independent behaviour.
