Does your Factory Floor Historian have the seven indispensable power features that enable real-time data insight? The essential Historian checklist reveals that you don’t need more data; the key is the right Historian.

It’s hard to believe but collecting factory floor data dates to Ford’s 1913 Model T production line in Highland Park, Michigan. No, they didn’t have automatic data collection. What they had were people who recorded information on every Model T coming off the production line. Steel filing cabinets filled with those production records were the historians of that era.

Today’s production runs are, of course, faster and more sophisticated with a variety of run sizes and all manner of options, testing sequences and quality checks. And just like in 1913, that data needs to be analyzed and archived. Today, however, instead of filing cabinets, we have data historians to hold the data.

And unfortunately, it’s just as hard to use the data in many of today’s historians as it was to use the production records in those old filing cabinets.

Indispensable features of a Factory Historian

Historian applications serve a variety of purposes. Some simple historians (a.k.a. data loggers) collect a few pieces of data for a short period. Some collect vast amounts of data that are transferred to an enterprise-level data lake. Some are designed to easily ship their data to Excel for quick analysis. Others offer sophisticated analysis capabilities that provide direct insights into a process’s efficiency and productivity.

Factory Floor historians have a range of capabilities, and many have particularly glaring weaknesses. Some are weak at data collection, supporting only a single PLC type. Others are weak at normalization, data modeling or analysis. Some can’t publish data to today’s digital systems. Many older historians are insecure, especially those designed before factory floor cybersecurity became a requirement. Other flaws include installation complexity, insufficient triggering mechanisms and cost.

When planning a Historian application, the key first step is to understand your objectives, both today and tomorrow.

What data do you want to collect and from what devices? How is that data currently formatted? Do you want the Historian to normalize, scale and add metadata to the raw data? Do you want it to be both a data collection and an analysis tool? Or do you prefer to separate the data collection and analysis functions?

No matter how simple or complex your application is, the following checklist can guide you through the selection process. The most indispensable features of a Factory Floor Historian are:

Connectivity: The ability to ingest raw machine data from your PLC, I/O system or network device is critical. More connectivity is not better. Support for hundreds of drivers you will never use provides no advantage. Support is much more important than the number of drivers. Knowing that the product is based on a reliable connectivity source that provides excellent support is more important than a large driver set.

Normalization / Scaling: Raw machine data is rarely in a format usable by enterprise applications. And more often than not, the same data point in two side-by-side systems will be formatted differently. Normalization and scaling is a requirement for your historians.

Modeling: Data modeling (collecting a group of related data together) is now, thanks to Smart Manufacturing and Industry 4.0, a necessary requirement. It would be nice to say that Historians should support both standard and user-defined custom data models. However, there is such a variety of standard models, defined in many different formats, that supporting them is difficult for the purveyors of Historian technology. If your company defines corporate models, it is best to inquire if your particular model can be loaded into your chosen Historian.

Flexible Triggering: Triggering is about on-demand data collection from a process. Data collection should occur on a user-defined schedule, at the end of shift, when a process ends or when some kind of process upset happens. Your application data collection and diagnostic data collection are seldom scheduled, so the ability to trigger data collection on a wide variety of events and values is important.

Transferring & Publishing: Once data is collected, it is more useful if it can be transferred somewhere or published. Transferring data can be as simple as copying a set of data to a USB stick (if your corporate standards allow it) or copying a CSV file to some server where it can be consumed by another application. Publishing, which is slightly different than transferring, means making some select pieces of data (usually encapsulated in a model) available over an open protocol like MQTT, MQTT SparkPlug, OPC UA or REST.

Cybersecurity: This is a new requirement that depends on your specific application and the cybersecurity policies of your plant. Cybersecurity requirements can vary from no security to compliance with a standard like IEC 62443 or with the CISA guidelines or the European Cyber Resilience Act (CRA).

Time Sync: All time-series data must be timestamped at the source using a common reference such as Network Time Protocol (NTP), Precision Time Protocol (PTP) or internal real time clock.

Other considerations

Beyond the indispensable features of a factory floor historian, there are three other important considerations:

Simplicity: As with most other products, the more features a Historian offers, the longer and more costly is deployment. Increased complexity always increases deployment and ongoing maintenance costs.

Footprint: Historians can be deployed as a hardware module or downloadable software. The advantages of downloadable software include unlimited disk space and no additional hardware requirements. Just create a new VM for your Historian. The disadvantages include the deployment complexity and ongoing subscriptions. This is where the interests of plant personnel diverge from the interests of an Integrator.

Software historians are preferred by integrators as they make life easy for the Integrator. A software historian can be downloaded, integrated into a broader application, tested and delivered with little hassle. Unfortunately, that leaves the plant with ongoing deployment costs for as long as that Historian is in service.

Price: Subscription pricing models are much more costly over time. You pay forever to use it, whether you use it once or twice a year or continuously.

Goldilocks finds the “just right” Gistorian

There are a large variety of Factory Floor Historians, everything from simple data loggers to large database systems such as OSI-PI to PLC-rack modules capable of high-resolution PLC data tag capture. These systems are often overly complex, expensive or lack one or more of the indispensable features listed above. Just like Goldilocks, factory floor operators could only choose from under-featured solutions (lacking one or more of the indispensable features listed above) that don’t fit or are complicated, over- engineered and expensive solutions.

Real Time Automation’s new PLC Historian fixes that. The RTA PLC Historian is easy to install and fast to configure, with just the right set of features for most time-series data collection applications. Tags from multiple PLCs are captured, normalized and saved, user-defined models are filled, published on demand without subscriptions, licensing constraints or reliance on third-party middleware.

With configurable storage up to 1 TB, a complete suite of publishing protocols (SQL, HTTP, FTP, WebSockets, USB, MQTT and email) and direct integration with InfluxDB for visualization and analytics, the Historian is an invaluable tool for plant floor operations, maintenance and process engineers.

John Rinaldi, Chief Strategist and Director of Creating WOW!, Real Time Automation (RTA)