FAQ on continuous monitoring systems, building management systems, OPC UA & API 

In our webinar “Continuous Monitoring Systems & Building Management Systems” we outlined several differences between building management and continuous monitoring systems. For example, a BMS relies on real-time information for control, while proof-of-compliance is achieved with a CMS using historical information. We describe other differences that help decide where each (or both) are appropriate. We also touch upon situations where the systems can interact through communications methods like OPC and API. 

During the webinar we were able to answer many questions, but not all. So here are our answers below…

M asked: 
•    “Is there a regulatory definition (from FDA or other regulatory bodies) of BMS vs CMS?”  

The short answer is no…

The FDA (and other agencies) have a regulatory requirement that you control your manufacturing environment to keep environmental parameters within limits that protect and preserve product quality.  To prove that you have controlled these parameters successfully, you must monitor in a way that data is recorded securely.  

However, regulatory agencies don’t specify tools or systems for monitoring or control of environments. Therefore, they don’t define terms for building management systems or continuous monitoring systems. The focus of regulators is always on the safety, quality, and efficacy of the product. 

This brings us to what regulations do address - cGMP.  The “c” stands for “current”. We can interpret this as established technology and practices used by others who manufacture a similar product.  The product you are working with defines whether the environment it is manufactured or handled in must comply with cGMP. The result is that if people in your business are typically using a BMS and/or CMS, the regulatory body will expect to see a BMS and/or CMS, even if they haven’t defined these systems in the regulations.

B asked two questions: 
•    “Can you provide supporting data/documentation for the API and OPC interfaces?”  
•    “Can you have a communication-focused training for OPC and REST interfaces to BMS, explaining advantages of each for different interface needs - real-time transfer, (batch) historical trends, etc.”

There isn’t an interface in viewLinc that is used to send data from viewLinc.  Rather, the viewLinc server will respond to queries directed at it using either API or OPC interfaces.  To use OPC, we utilize an intermediary server that translates OPC queries in the REST API.  

To get data from viewLinc using either protocol, the request would have to come from a system outside of viewLinc.  Because we have set this up as a read-only response-only system to these standardized protocols, there is no viewLinc specific data or documentation on the interface.

However, we have an application note that describes how viewLinc functions with OPC UA or the viewLinc API. 
“Integrating the viewLinc Continuous Monitoring System with other systems” 

Vaisala CMS project engineers can provide explanations on how OPC UA and viewLinc API can work with your systems. Simply contact your Vaisala sales manager or request a call here. 

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J asked: “Do you have a separate webinar for the Vaisala viewLinc continuous monitoring system?”

Yes – These two webinars linked below would provide good information on viewLinc’s capabilities: 

•    Innovative Automation in Laboratory Monitoring

•    A Future-Proof Monitoring System: Ensuring Your System Can Adapt to the Future of GxP

If you prefer to learn on your own, the viewLinc web page is a good place to start. There are many white papers and application notes, as well as infographics on software validation according to GAMP and device connectivity options for viewLinc.  

J asked: “Could the viewLinc CMS also perform the role of an EMS, for instance monitor particulate measuring systems?”

Absolutely.  The viewLinc CMS can accept inputs from particle counters.  Right now, we can accept these inputs as analog values into a datalogger, or through a Modbus interface directly into viewLinc.  Currently, viewLinc has two limitations on particulate monitoring.  First, the default scan rate of viewLinc is about every minute, so you may have to wait a minute to be notified of an out-of-specification condition.  Second, viewLinc reports aren’t yet optimized to present the type of data that are sometimes needed for particulate measuring, such as: rolling counts, interval counts, etc.  You can get this data in a report no problem; but it’s not optimized in viewLinc. We are working on this feature for customers who currently use viewLinc with particle counters. 
 

M asked: “Please define these acronyms:  MMI via OPC and REST API”

Yes, apologies for the jargon! MMI means “Machine to Machine Interface”.  That is a little vague and could describe a vehicle transmission as much as it describes a computer system.  For contrast, just think of the acronym HMI, which means “Human Machine Interface”.  That one is super clear.  

By comparison, the MMI in this case is simply the avenue by which one computer system interfaces with another to exchange information.  Maybe a plainer way to say it is that it is an MMI that a BMS would use to collect data from a CMS.

OPC and REST API are two different ways to do this, each quite different.  OPC, stands for “Open Platform Communications” (See: https://en.wikipedia.org/wiki/Open_Platform_Communications).  

Open Platform Communications is a 25-year-old standardized protocol that enables data communication between control devices from different manufacturers and a control system.  It is frequently used in building automation, manufacturing, process control, etc.  To use OPC with viewLinc, you set up an OPC server (with software from us) and this OPC server acts as an intermediary between the BMS (or other system) and viewLinc CMS.  OPC queries come from the BMS and data is returned from the CMS in a read-only connection.

REST API is an API (Application Program Interface) based on a software architectural style called REST (Representational State Transfer) 
(See: https://en.wikipedia.org/wiki/Representational_state_transfer). 

Simply put, REST API is a communication protocol that is well suited for network-based client-server applications and is designed for use at Internet-scale.  Again, this is just a language or protocol that can be used by another system (like a BMS) to query the viewLinc system for read-only data.

We hope these answers are useful.  Feel free to put any follow-up questions in the fields below!