The November ISA Toronto dinner meeting featured Kevin
Martyn from Magnetrol as the guest speaker who provided the members with an
enlightening presentation on SIL – Safety Integrity Level. Kevin explained how
data originally developed for SIL (Safety) applications could be used to
increase reliability throughout the plant. However, the highlight of the
evening was when one of the many acronyms tossed about that night invoked the
universal blank stare of “ huh?” from
the audience.
Seeing that not many people were familiar with the term FDT,
and that it was not an integral part of his core presentation, Kevin offered to
provide and overview at the end of the meeting, the following is a summary of
this new and exciting technology.
What is FDT?
According to the people from the FDT Group, “FDT (Field Device
Tool) technology standardizes the communication interface between field
devices and systems. The key feature is its independence from the communication
protocol and the software environment of either the device or the host system.”
In other words you can take a field bus instrument
that is FDT compliant and communicate with it regardless of which manufacturer
made it or the protocol it was designed to use. For example if you have a HART
based transmitter and connect it to one of the FDT client software packages you
will be able to connect to it using a standard Windows based computer,
hand-held device, or even the main DCS. The FDT user interface will allow you
to access advanced device-specific data, functions and communication
capabilities, configuration parameters and much, much more – either on the
bench or while the device is still in the loop.
But what really makes this one of the most innovative
technologies in the field today is that you can replace the HART transmitter
with another brand, or even one with a different communication protocol like
Profibus , or Foundation Field Bus, and still use the same application
software, making it a truly vendor-independent user interface.
The concept is similar to how the computer industry
handles all the different printers that can be connected to a computer i.e.
each printer comes with its own device driver, allowing the operating system to
interface it to the user application.
These printer drivers are based on a “Windows” standard, so it does not
matter if the computer is from Dell or HP.
Many of the instrument manufacturers that have
adopted the FDT technology supply these drivers (called DTM -
Device Type Manager) for each device or group of devices they
manufacture. The DTMs provide functions for accessing device parameters,
configuring and operating the devices, and diagnosing problems. DTMs can range
from a simple Graphical User Interface (GUI) for setting device parameters to a
highly sophisticated application capable of performing complex real-time
calculations for diagnosis and maintenance purposes.
The end-user runs a FDT container program called a "frame
application” that defines a set of interfaces between the hosting
application and the DTMs, these can be device configuration tools, control
system-engineering tools, operator consoles or asset management tools. The
frame application also contains the communication component (really just
another driver or communication DTM) to interface the host system with the
specific fieldbus communication (e.g., HART, PROFIBUS, FOUNDATION fieldbus,
etc.).
The FDT Group (www.fdtgroup.org)
is an open, independent, not-for-profit collaboration of
international companies (56 of them as of November 2006) dedicated to establish
an international standard with broad acceptance within the automation industry,
their website lists the manufacturers that support the FDT technology and also
provides access to download the DTMs for each supported device.
The DTMs can then be loaded into a Windows based
frame application (such as Pactware,
Fieldmate, or Fieldcare) allowing the end-user access all
the device parameters. Pactware is free and can be downloaded from the PACTware
website at www.pactware.com.
If you like to see this as a topic at one of our future dinner meetings, let us know by emailing us at office@isatoronto.org and we’ll set it up.