FDT Technology

Why do we need FDT?
Many automaton devices are complex and need parameterization before operation can start. This is particularly the case within process industry (valves, flow meters, actuators etc), but lately also within discrete factory automation (motor starters, frequency inverters, etc.). Historically this parameterization was made locally on the device, with a keypad or a serial cable and a laptop, and this is, in spite of, the fact that the device was communicating with a fieldbus for process control. FDT enables this configuration to be made remotely over the existing fieldbus connection. The device manufacturer makes tailor-made graphical user interfaces for their devices and includes functions like Asset Management for device maintenance and database for parameter management of their devices. FDT gives the plant owner a uniform way to organize and maintain the plant automation assets, the automation devices.

How FDT works
FDT technology comprises three key components: the Frame Application, Device DTMs, and Communication DTMs. To better understand the functionality of these components, consider the analogy of the Internet -- a standard web browser allows users to view countless web pages created by many content providers. The host system supplier typically creates the Frame Application, just as Microsoft supplies the Internet Explorer web browser. Just as a web browser opens a web page that contains code from the company that makes the web page, an FDT frame opens the Device DTM, which is the plug-in software from the device vendor.

Similar to a web browser, the Frame Application has menu bars, toolbars, and a navigation tree. Visually, the frame application surrounds the device vendor’s DTM. Like opening a web page from a ‘favorites’ navigation tree, a user can navigate down a tree that lists the field device tags, click on one, and open the device vendor’s DTM inside the frame. And, like web pages that let users interact with a reservation system or a shopping service, the Device DTMs let the user interact with the field device in a wide variety of ways. The Device DTM vendor can create a graphically rich user interface that does virtually anything possible in an advanced Windows PC-type interface. The third part of the technology, the Communication DTM, provides a standardized communication Application Process Interface (API) inside the PC, interfacing between the Device Vendor’s DTM and the host system’s specific driver that handles passthrough communications from the PC down to the fieldbus interface card.

The host system vendor supplies a Communication DTM (comDTM) for each supported fieldbus protocol. This ensures that the details of the PC, network, interface cards, and passthrough protocols of the host system, are transparent to the device vendor’s DTM. This correlates back to the internet analogy where: the web page is transparent to the PC it’s running in, the brand of the network interface card in the PC, or whether communication is DSL or broadband cable.

Typical frame applications are
Pactware from The PACTware Consortium e.V. (freeware)
FieldCare from Endress & Hauser
Field Control from ABB

HMS is supplying the Anybus comDTM and the hardware to access the fieldbus data and its devices.
Click here to read about Anybus comDTM