When we finally get smart instruments communicating effectively, what will we do with them?
The basis for smart instrumentation is the intelligent devices on which they rely. The definition of an intelligent device in the ISA108 standard is, "a device that in addition to its basic measurement or control purpose also has digital communication capabilities and supplementary functions such as diagnostics and the ability to share this information with other devices on the network."
As a result of the many discussions on wireless and other forms of digital communication between these intelligent devices, and the need for smoother integration, there is a significant amount of work presently underway in IEC standards development. Under the auspices of TC65, Industrial-Process Measurement, Control and Automation, we have subcommittees working on SC65A, System Aspects; SC65B, Measurement and Control Devices; C65C, Industrial Networks; and SC 65E, Devices and Integration in Enterprise Systems.
The guiding principle for all this work is the digital factory concept as the basis for developing a series of standards containing information on all automation assets in a common format, including traceable asset properties throughout the plant lifecycle from design through retirement/replacement. Doing this requires the following five views of information: Construction (C)–constructional properties (e.g. type of connectors); Function (F)–functional aspects supported by the automation asset (e.g., application functions, operating functions, tasks); Performance (P)–characteristics of the functional aspects (e.g., rated values, cycle time or start times, threshold levels, energy consumption); Location (L)–indicates the position of the automation asset in the plant (e.g., relative location, absolute location, global position coordinate, location identification for specific domains); and Business (B)– reflecting the commercial aspect properties of the automation asset (e.g., price, delivery time or quantity in a package unit).
In addition to providing stewardship of the digital factory concept, the outputs from the joint SC65E subcommittee working with ISO 184/SC5, Interoperability, Integration and Architectures for Enterprise Systems and Automation Applications, are two documents: Technical Report IEC/TR 62794, Industrial-Process Measurement, Control and Automation—Reference Model for Representation of Production Facilities (Digital Factory), and IEC 62832, Digital Factory, which defines a comprehensive network of digital models, methods and tools that are integrated by a comprehensive data management system to represent the basic elements and automation assets, as well as the behavior and relationships between these elements/assets.
IEC committees deal more with the system aspects of industrial automation, such as how it's set up and the equipment installed, while ISO concentrates more on how automation is applied, for example, in managing production unit resources and the planning and archiving aspects of industry. Therefore development of the digital factory standards must cover both perspectives of system- and application-related intelligent devices. Hence, the need for coordination between these two groups on not just this standard, but many others as well.
There's a lot of activity underway within the global standards organizations to help you build, define, deploy and manage the data from smart instrumentation. However, the standards only provide the tools to make it possible to have and integrate the devices into a system.
The challenge that remains and, more importantly, is the justification or reason for using smart instruments in the first place, is how to most effectively use the intelligence in smart instruments, which is something we'll be sure to cover in the future.