FDT Tools
FDT-Specification Basics
ifak system GmbH
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Summary: Objects in the FDT concept
DeviceDTM
A DeviceDTM is a DTM for fieldbus devices. It provides all nec-
essary functionality of the devices in software. To achieve this, it
employs the communication interfaces of the CommDTM.
Within the FDT concept the DeviceDTMs form the lowest level
in the system topology. They use the services of other Comm-
DTMs to access its field device. The parameters of the device are
made available to the user by a number of ActiveX dialog HMIs
which can be called from the DTM.
ActiveX
The ActiveX are the "visible" components of a FDT application
(as far as device functionality is concerned). DTM and channel
objects provide interfaces for the configuration, diagnosis, docu-
mentation and parameter manipulation, while the ActiveX pro-
vide an easy way of data presentation and user interaction.
CommDTM
A CommDTM is a DTM which offers communication function-
ality to other DTMs. These DTMs may have been developed for
a hardware (e.g.
is HART USB
device) or a software (e.g.
is HART OPC Server
) communication interface. The Comm-
DTM itself can employ the services of another CommDTM
(gateway functionality). To allow communication with its under-
lying hardware or software the CommDTM offers a number of
communication (Comm) channels.
