6 May 2020

Simplifying connectivity to existing HART devices

Smart instruments have been available since the 1980s with digital communication ranging from HART up to today’s Profinet alternative. Processing power and memory of these devices has eclipsed that of a family PC from 1990. However, is this intelligence being utilised, and could your installed devices be connect to IoT applications?

NAMUR Open Architecture (NOA)

Industry 4.0 requires data, and “Smart Instrumentation” have this in abundance, supplying valuable information into how well your process is functioning; however we still see an issue with stranded data at brownfield sites.  How is the intelligent data from smart instrumentation released for digitalisation?  NAMUR identified this as an issue for the industry and developed a new standard called NAMUR Open Architecture, (NOA).  With this being a new approach, we anticipate there being questions, and we don’t want to add interfaces to an existing installation that could cause problems with the main process automation layer.  Here we take a look at the potential questions you may have with this type of connectivity. 

Will this approach interfere with the current process value? 

Quite simply, no.  Your site has been running for 15 years with all the 4-20mA devices functioning fine except for standard recalibration and device failure. NOA has considered this, and the approach is to separate the HART from the 4-20mA connection and take this to a secure second platform for cloud applications using OPC UA communications. Your process value is safe and unaffected by this connectivity. 

How is security handled? 

This is vitally important, and we now have a new layer of security to consider as we have opened the digital connectivity to the instrument. What’s stopping a cyber-attack from adjusting your empty distance on a level sensor and stopping production? The standard considers this, with all communications from field devices being strictly one way; the device can only push data to the NOA gateway. 

Do I have to send the data to the cloud? 

With the security to the instrument established, the next question is Ethernet security.  The new Siemens CC240 NOA device has OPC UA connectivity and MindSphere onboarding capability.  So, we have two choices. 

  • The data can be sent to MindSphere using the high security standard designed into this platform.  Your data can then be used across multiple applications, and upgrades to applications will happen automatically and your data is available 24-7. 
  • “On-Site” solutions.  A number of industries strictly forbid data to be sent off site.  The CC240 can be used to send OPC-UA data to your local applications on edge-based devices such as Siemens WinCC unified.  The digital potential of a HART instrument can now be realised; something that is quite often not labelled as an intelligent device. 

Now the process values and diagnostic data is available on an OPC UA platform, this increases the opportunity to proactively engage in an information driven basis to plant operations, manufacturing and maintenance.  A simple example of this is being able to serve information in a user-friendly way to allow maintenance and operational decisions to be easily actioned without increasing complexity. 

If you want to know more, please feel free to ask, or check out my online video tutorials here

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