An experienced technician or engineer immediately understands that “level” means the same as “liquid height” in two different tank gauges’ data tables. But a computer? Not so much.
Hence the need for the Process Automation Device Information Model, or PA-DIM. At its simplest, PA-DIM is a common language for describing device data regardless of protocol, type of device or manufacturer. And as organizations endeavor to use advanced analytic tools to gauge the relative performance of devices and assets across diverse fleets, PA-DIM effectively eliminates the semantic ambiguities that would otherwise make such comparisons meaningless or impossible.
The process automation industry uses several standards-based automation protocols, including HART, Foundation fieldbus and PROFIBUS PA to represent information made available by field instrumentation. Since each automation protocol represents field device information differently, consistently integrating that data with higher level IT systems is difficult at best.
PA-DIM is the information model that makes such tasks possible. It was created by a joint working group of FieldComm Group and the OPC Foundation in 2017 and they completed version 1.0 of the
PA-DIM Specification in June of 2020. Work continues to add support for additional device types, and the active participation of FieldComm Group and OPC Foundation member companies is encouraged.
The scope of the working group is to:
- Prepare and propose enhancements to the OPC UA Unified Architecture for Devices companion specification.
- Ensure compatibility between FDI technology specifications and the OPC UA Unified Architecture for Devicescompanion specification.
- Specify and maintain OPC UA information models for process automation devices, initially based on NAMUR Core Parameters as set forth in NE document 131, “NAMUR standard device – Field devices for standard applications,” including assignment of semantic identifiers according to the IECCommon Data dictionary and/or eCl@ss.
- Enhance the OPC UA information model for FDI based on requirements from industry, such as NAMUR Open Architecture, Industrie 4.0 and IIoT initiatives.
Recent FieldComm Group technology registrations
Testing and registration is key to interoperability and ensures specific devices and systems conform to the same standard. FieldComm Group is one of the only automation industry organizations with a registration program requiring mandatory testing of critical elements of its technologies. Today, FieldComm Group's testing and registration effort encompasses FDI, Foundation Fieldbus and HART host systems and field devices, as well as physical layer components such as power supplies, cables and device couplers. One of the founding principles of FieldComm Group is the support of interoperability—the ability to operate mulitple devices from multiple manufacturers, in the same system, without loss of functionality.
Products bearing the Foundation Fieldbus or HART Product Registration symbols have undergone a series of common test administered by FieldComm Group. End users can select the best device for a specific measurement or control task and know that device will provide a consistent level of functionality and interoperability regardless of host system or other devices used. Testing and registration enables a user to achieve the best return on their investment. FDI-enabled products further ensure that products can be integrated in a consistent and familiar way across varying systems—thus enabling enterprise-wide support and data access to operate more effectively.
More than 100 registrations of products ranging from actuators to temperature transmitters were completed between September 1, 2020, and September 30, 2021. View a list of these recently registered products here.
Find a complete list of all registered hosts and devices in the Registered Products section of www.fieldcommgroup.org.
