CPAC Connectivity Initiative (ConnI)

Background and Overview

Over the past 20 years, Process Analyzer systems have evolved into rather sophisticated systems, the main attributes of which mimic the hierarchical connectivity architecture of advanced process control systems. At the lowest level, there are the sampling systems and sensors (Level 0), the analyzer controller (Level 1), gateways to the DCS, data servers, workstations and user interfaces (Level 2), historians, workstations etc. (Level 3) and long term enterprise based historians, remote workstations, maintenance tools etc. (Level 4). As such, there are no guidelines today which facilitates the integration of different analyzers from different suppliers into a single coherent system including the consolidation of different user interfaces in workstations at level 2 and above. The absence of these guidelines has created major hurdles for many analyzer vendors in selecting a connectivity solution that guarantees its broad acceptance within the process analyzer supplier and end-user community.

ConnI aims at developing a generic Connectivity Model and Architecture that will enable the use of an Ethernet based communications back-bone and industry standard communication protocols (e.g., TCP/IP) which in turn will allow the peaceful co-existence of higher level protocols (e.g., http, OPC, etc.) as a means of integration and communication between different system components. The ultimate objective is to ensure the seamless integration of analyzers from multiple vendors while taking full advantage of consolidated user interfaces and datalinks to the process control system. In addition, the architecture needs to support remote access from any workstation within the enterprise wide network to any analyzer for full troubleshooting and/or maintenance support.

ConnI is supported by a non-affiliated international ad hoc group composed of end-users such as Dow, ExxonMobil, Dupont, BP as well as large and small analyzer vendors such as  ABB Automation, Siemens Applied automation, Emerson Process/Rosemount Analytical, Panametrics, Servomex and many others looking for guidance in terms of common, industry-wide acceptable connectivity solutions. Although ConnI operates under the sponsorship and umbrella of CPAC (Center for Process Analytical Chemistry) at the University of Washington in Seattle, it is an open initiative; participation is voluntary and available to any member of the process analytics community, end-user or supplier.

ConnI Goals/Objectives

ConnI's main goal is to develop a Connectivity Model based on a functional understanding and description of the overall Process Analyzer System. The latter has been described in terms of four functional domains (see Fig. 1) and some of the issues and opportunities ConnI will attempt to address, are summarized below:

• The Measurement Domain (the analyzer proper and its associated analytical and sampling system sensors are part of this domain/dimension) Issues are:
  • How/what the analyzer communicates with the other domains; the distinction between analysis only data (intended only for the process control host system) and operations/maintenance data is extremely important
  • How the analyzer interface with NeSSI based sampling systems (this is the link between NeSSI and Connectivity)
  • Adoption of Ethernet and TCP/IP as the datalink layer/base protocol will finally allow for "plug-and-play" integration of analyzers in an on-line system (an important cost-to-build and cost-of-ownership issue)
• The Process Control Domain (the primary customer of the analyzer data)
  • With the wide acceptance of OPC (OLE for Process Control), there is for the first time an opportunity to develop an industry standard data link interface for analyzers which would be the digital equivalent of the 4-20 mA interface.
  • Achieving this goal will for the first time allow all analyzers (from the simplest pH/conductivity type analyzer to the most sophisticated GC/Spectrometer type) to transmit their data digitally to the control system with a quality indication (good/bad), no range limitations etc..
  • As the need for a "standardized" but open data link interface is pressing, ConnI will endeavor to develop an OPC based datalink interface specification and use the ConnI community to provide feedback and acceptance of this new datalink interface
• Analyzer Operations/Maintenance Domain (operations and maintenance support for the analyzer)
  • There are several opportunities here to provide guidance in terms of using web-enabled protocols/technologies to simplify the user interface for any analyzer, the archiving of raw data and the tools to evaluate the performance of the analyzer based on the raw data.
  • Facilitating this process will go a long way towards improving the reliability/performance of analyzers; the impact on cost-of-ownership will be significant
• Enterprise Domain (essentially what is involved to have or allow remote access to analyzers from anywhere within the company)
  • The use of advanced on-line analytical techniques requires technical support often beyond the capabilities of local plant personnel. The ability to access any analyzer on a world-wide basis from anywhere within a company becomes an important support issue.
  • ConnI will attempt to highlight the tools etc. that are available to comply with the security and control requirements associated with remote access. In addition, the proper design of the connectivity architecture and the correct use of hubs, switches and routers etc. will also be highlighted to either limit exposure to or be compliant with the enterprise wide networks.

ConnI will be a major vehicle for illustrating the importance of a systems approach to on-line process analyzers. A stand-alone analyzer, no matter how sophisticated and capable it may be, has no value unless it can qualify and deliver its analysis data to a control, safety or environmental host system and provide for an efficient user interface (local and remote) to ensure its reliable performance. In addition, most analyzer vendors are looking for some guidance in this area as there are several connectivity solutions possible and they would like to have assurance that whatever solution/approach they take, that it will not exclude them from any analyzer project because of technical incompatibilities.

We are looking forward to working with our ConnI partners as this is an unique opportunity to address connectivity on an industry-wide basis as opposed to individual end-users or suppliers trying to lead the effort.

Chronology and Log of ConnI Events and Milestones

The following table shows significant events and milestones in the ConnI  program to date (organized in a chronological order) along with hyperlinks to related documents and presentations. Many of these links are to Microsoft Office documents (Word documents and PowerPoint presentations) in their original form (not html pages) and will require that you have the supporting applications on your machine to view them. In most all cases, there is also a version the documents in a more universal Adobe Acrobat reader (PDF) format that can be accessed by clicking on the icon.