The most significant updates to the Foundation technical specifications are a revised series of function block and transducer block profiles, as well as requirements for H1 (31.25 kbit/s) device replacement that are now part of the Fieldbus Foundation’s device registration process. This enhancement enables the H1 interoperability test kit to verify consistent behavior between device and host implementations in fieldbus-based control systems.
End users are seeking increasingly automated replacement of intelligent devices. Device replacement automation makes it easier to reproduce an existing FOUNDATION device configuration (including function blocks and parameters) in a newer instrument by enabling a minimum set of functionality to exist so end users can get their process back up and running quickly and simply. This enhancement allows for final configuration to be completed after other critical tasks associated with the process outage have been addressed. This saves time and money and simplifies stocking of replacement devices.
Fieldbus Foundation Director-Fieldbus Products Stephen Mitschke commented, "The Foundation recognizes that ease of device replacement is an important concern for engineers and technicians in process plants. We see these updated specifications as a valuable opportunity and a first step in a series of things we can do to provide more value to the end users. It’s another example of our commitment to continuous improvement and being an end user driven standard."
Automation of device replacement allows the configuration in an existing field device to be restored in a newer version of that instrument without manual intervention. This ‘plug and play’ solution ensures features are consistent between different generations of devices without reengineering the host configuration or changing any other element of the H1 network other than the new instrument.
In addition to device replacement, the specification update provides improved positioner profile in fieldbus devices. This technology supports organization and integration of advanced device diagnostics within fieldbus systems. It provides standard definitions for positioner transducer blocks and includes parameter structure definitions for better data organization with fieldbus devices, including partial/full stroke test (PST/FST) of valves.
The new specification release also includes definitions for discrete process variables clarifying how variable values are interpreted in conjunction with state tables, as well as several new or updated application and technical notes.
For more information, please visit the Technical Specifications page of the Fieldbus Foundation’s website at www.fieldbus.org. You may also view the Spec Index for a full list of specifications included in the Foundation Technical Specifications package.