FDI (Field Device Integration) is an emerging standard that in the near future will start to gain prominence in industry. It was created to offer greater compatibility of EDDL-based (Electronic Device Description Language) networks such as HART, Foundation Fieldbus, Profibus & Profinet, and will allow these networks to be more easily integrated with each other. Via existing FDT technology FDI will also allow EDDL-based systems to be integrated into a host of other industrial networks.
Glenn Schulz explained the reasoning behind the creation of FDI. “On the surface, EDDL appears to be a common language to specify device behavior and device characterization. However, the different EDDL-based networks have each developed a very unique dialogue, to the point where they are not compatible.
“This means that when an instrument manufacturer goes to market with a new instrument, if they are releasing it on multiple buses, they will need to go through a completely different certification processes – with a different EDDL file for each – even though the device is the same for each one of the networks.”
EDDL harmonization
The different flavors of EDDL has also posed problems for end-users because they need to seek out the right EDDL file for the network onto which they want to deploy a new device.
One of the major requirements of the FDI standard which has been developed by the FDI Cooperation,* was therefore to harmonize the EDDL language so that each of the automation foundations are able to use exactly the same language, with some allowance for the uniqueness of each of the networks.
“The release of the FDI standard will result in the creation of a single, common, interpreter for all the different EDDL files across the EDDL-based networks. This will significant simplify the architecture from a host perspective and should dramatically improve interoperability going forward,” said Schulz.
The FDI standard will also add improved graphics capabilities for device configuration. “EDDL has been somewhat limited in terms of what it can do graphically,” continued Schulz. “You can add graphics, but they are not highly interactive, and you do not get a rich, graphical user interface feeling. FDI, however, will bring this capability to EDDL.”
FDI will bundle these capabilities into a device package that will incorporate a collection of files – including the device description, the device definition, business logic and a user interface description. So, FDI-enabled devices will only require the matching FDI device package that holds all the information and software needed to configure that device.
“One of the key considerations in the development of FDI was that, from the ground up, it was designed to be compatible with the FDT standard – and to avoid even more competing industry standards!”
So, FDI is designed to support EDDL-based standards. However, there are many other networks being used in industry today that need to be integrated, in order to build a complete solution. A method was needed to bring them all together, to create scalable solutions. This is where the FDT standard comes into play, with its ability to standardize the communication and configuration interface between all field devices and host systems.
The FDT technology provides a common environment for accessing features of a device via a DTM (Device Type Manager). A DTM, which is supplied by the device vendor, is a software representation of the device and it can offer a host of functions. It can assist with device configuration, diagnostics; it might be able to handle troubleshooting and will also include a device manual. The network communication devices are also represented by a DTM making the standard highly flexible for the end user.
“Although the FDT standard and the FDI standard share many similarities, they are not the same,” said Schulz. “An FDI host, for example, is not able to support DTMs. It can only support EDDL-based networks. This is why we talk about integrating FDI into FDT.”
Integrating FDI into FDT
Explaining further about how FDI will be integrated into an FDT-based host, Schulz explained that any number of DTMs can be loaded into the FDT host, which is able to talk to any number of industry networks. “When FDI-based devices do start to appear, a special DTM – called an FDI DTM – will be created. Inside this FDI DTM will be the common EDDL interpreter, which is needed for the FDI standard, as well as the other components that support the FDI standard.
“With an FDI DTM solution all the FDI functions will be fully enabled within FDT with no limitations. All FDT DTM features are also fully enabled, making it possible to take DTMs for devices on any of the industrial networks or fieldbuses and use them within this integrated solution.”
Earlier this year at the Hannover Fair, CodeWrights, an FDT Group member, was able to demonstrate how FDI packages, inside an FDI DTM are able to communicate with different devices, showing how far the technology has now come.
As field devices gain ever more intelligence, they can provide huge amounts of data, which, if turned into useful information can offer big benefits. The creation of a standardized way to describe automation components and to communicate with them is therefore becoming increasingly important. Without it, the true potential of decentralization, transparency, integration and a central view of all data and functions cannot be fully realized.
* FDI has been developed by a group of industrial technology foundations and suppliers of process control systems and field instrumentation. Its specification is based on close cooperation with end users and end user organizations, and the requirements of NAMUR and WIB, the process automation users’ association, have been included in its specification, enabling it to offer an intelligent migration strategy from the past to the future using state-of-the-art and best-of-breed technologies.
FDI Cooperation members include five major automation foundations - FDT Group, Fieldbus Foundation, HART Communications Foundation, PROFIBUS & PROFINET International, and the OPC Foundation. Major automation vendors supporting the organization include ABB, Endress+Hauser, Emerson Process Management, Honeywell, Siemens, Yokogawa and Invensys (now part of Schneider Electric).
By: Suzanne Gill, Control Engineering, Europe
A whitepaper, produced by FDI Cooperation LLP provides an in-depth look at FDI technology. This can be downloaded now from the whitepaper section at www.controlengeurope.com
The following FDT Group produced video provides an in-depth look at how FDT incorporates the FDI standard.
