How smart I/O enhances distributed control

Installing smart input/output (I/O) during an upgrade or migration can provide personnel with near-real-time data at their fingertips

By Matt Smith September 23, 2020

Over the past decade, the digital transformation wave flooded the manufacturing world with intelligent data. To reap the benefits of this Big Data and stay competitive, manufacturers are turning to smart manufacturing technology and platforms, such as the Industrial Internet of Things (IIoT), data analytics, cloud and edge computing, virtual reality (VR) and the like. Leveraging smart technology and devices to access, capture, store and analyze mission critical data is vital to running a facility and meeting customer demand.

For many manufacturing facilities, however, outdated distributed control system (DCS) limitations prevent open communication to smart field devices, subsystems and higher-level enterprise-wide systems, making it difficult for personnel to access critical data. To digitally transform their operations, manufacturers are looking to update or migrate their legacy DCS with smart devices to improve asset utilization, increase connectivity and enable near-real-time, data-driven decision-making throughout the enterprise. It also is the ideal time to either upgrade or replace conventional analog-based instrumentation or add smart functionality and software to existing digital instrumentation.

Some manufacturers jumped on the smart technology bandwagon early and are using microprocessor-based or smart transmitters. Today, however, many of those same facilities have yet to take advantage of the available advanced data and diagnostic capabilities and, in some cases, multiple process variables (MPVs) that come with them. To do so, they must carefully weigh the pros and cons of installing smart input/output (I/O) and leverage the latest asset management software (e.g., Rockwell Automation’s FactoryTalk AssetCentre) to manage the data.

Why smart I/O?

Smart transmitters make a technician’s job easier when coupled with a digital communication protocol (e.g., HART) as they can easily setup a control element and access and share critical data via mobile devices onsite and in the field. If smart I/O and asset management software are not installed, facility personnel often are left without the full capabilities or functionality from their new smart technology or handheld devices. This smart technology, coupled with the proper software, is key to remotely accessing valuable data, such as a device’s performance, to determine deviations from normal calibrated settings.

The benefits of smart I/O and smart transmitters, coupled with asset management software, include the ability to:

  • Help monitor a facility’s factory automation system and reduce downtime due to unauthorized actions or failing devices.
  • Provide diagnostic data directly to a human-machine interface (HMI) and asset management system, reducing troubleshooting time and increasing uptime.
  • Provide ease of transmitter/control element replacement with configuration setting downloads. Asset management software allows a technician to push the data down to a transmitter to a specific node ID (e.g., a Fieldbus device ID).
  • Offer MPVs — MPVs are generally available with one I/O connection to a device instead of selecting what MPV to transmit. Vendors include different information in their smart transmitters. For example, a mass flowmeter could provide rate, temperature, total and density variables, increasing the transmitter’s value.
  • Provide an electronic repository to help maintain and manage any hardware calibration and lifecycle management data all in one place when using asset management software.
  • Create electronic loop folders to house relevant instrument data and checksheets, reducing documentation time by up to 50% as technicians can access the electronic data at any time.
  • Scan and record valuable data via barcodes or radio frequency identification (RFID) tags applied to each instrument. This can be coupled with additional layers of software (including VR) to provide field access to all data related to a specific device for troubleshooting, reducing downtime.
  • Aid project tracking and eliminate the paper trail (i.e., file cabinet data sheets). Issues can arise when key personnel must rely on the paper trail for valuable information, as in:
    • What happens if the instrument sheets are lost?
    • What if personnel forget to record the asset ID on the paperwork?
    • Where does the paperwork get stored?
    • What happens when the control room calls and says a device is acting up?

A typical scenario is when a technician is dispatched to the field with a communicator and must then connect to the device and run queries for issues. Sending someone to remotely connect and diagnose the issue and then document any problems on paper takes time and money.

These issues can be resolved if the DCS has smart I/O to track the device data. Technicians can then use mobile handheld devices and software applications to remotely monitor and digitally document instrument calibration data and checksheets, as well as access the control system for testing and troubleshooting. In many cases, instead of operators or maintenance personnel going out to the field to connect to a device, HMI maintenance screens — along with properly configured alarms — can be developed to immediately alert them of a problem before it becomes critical.

Smart I/O complexities

So, with all these benefits, why not leverage smart I/O to access all that critical data? For many, it comes down to increased installation and implementation costs. Much of the expense is due to the I/O count per module. Some standard analog input cards, for example, may have 16 inputs, but smart I/O cards with digital communications protocol (e.g., HART or Fieldbus) may only have half that input, so the I/O density is less. The increased cost comes into play as additional smart I/O communications cards are needed, along with more I/O racks to house them.

The implementation process also comes with an increased level of complexity. Manufacturers will need to install the smart I/O and other necessary elements. Resource bandwidth may be a factor as companies seldom have the number of operators, engineers and maintenance people needed to execute the upgrade project, especially if it’s a full-blown legacy system migration. In this instance, finding a third-party partner with the familiarity and skills required to integrate and implement automation system components and technology is key to success.

In addition, manufacturers must know in advance what asset management software elements are required to get the full benefit of the diagnostic and other capabilities of the new system. Otherwise, the cost will increase as options are added later. Some key elements to look for in a smart I/O and asset management software combination is the ability to:

  • Manage device configuration files
  • Manage process device calibration, including scheduling and tracking
  • Manage and configure device type manager (DTM) devices using a process device configuration option
  • Log system events and user actions.

Other capabilities may be available as well (e.g., secure access and disaster recovery), but as with any hardware or software purchase, review all required elements ahead of time to leverage any cost reduction benefits of the project. Also consider where it all gets housed and whether a new computer system or a virtual machine is necessary to maintain the system.

Manufacturers must carefully review all these considerations and how they fit into their overall business needs, goals and objectives. A legacy system migration project is a great time to reevaluate existing hardware and software and review potential project costs against overall return on investment (ROI).

Plan and justify

Proper upfront planning is the best way to resolve any issues and justify a project. Using a front-end loading (FEL) approach, a team can develop a project execution plan based on proven best practices. They can successfully plan and budget using an itemized task checklist, such as:

  • Define a scope that aligns with the company’s business needs and requirements
  • Evaluate and select the best hardware and software options available
  • Develop an execution plan — along with accurate cost estimates — and a schedule
  • Develop total installed cost and total cost of ownership comparisons on different vendor options to maximize the ROI
  • Define and mitigate potential risks, such as resource availability, downtime, safety and the like.

For justification purposes, companies will need to look at the total installed cost and the total cost of ownership over the entire lifecycle of the investment. For example, think about how much that last transmitter or control valve positioner cost as it was failing without any indication. Is there data available on its daily operation? How many times has it failed in the past? Downtime costs and ROI are hard to determine in cases where data is not readily available.

Also think about the intangible assets and advantages. How much value, for example, is placed on peace of mind, knowing the system will alert personnel ahead of a failure and prevent potential emergency situations from occurring outside of or during normal working hours. Response time under these circumstances is critical to the safety and well-being of personnel and the manufacturing facility.

A smart industrial world

The industrial landscape is getting smarter. Modern control systems contain valuable technologies that can make significant improvements to operations and increase productivity. Installing smart I/O during an upgrade or migration can provide personnel with near-real-time data at their fingertips that now takes someone going into the field to gather.

It is critical a project team has the right knowledge and experience to overcome the potential challenges unique to automation. If resource bandwidth is an issue, engage a partner who has multiplatform experience and the skills required to successfully integrate and implement the automation system components and technology on the market. The right partner can help guide the project to success and deliver a higher level of system integration while maximizing the return on a smart automation investment.

This article appears in the Applied Automation supplement for Control Engineering and Plant Engineering.

Author Bio: Matt Smith is a senior consultant at MAVERICK Technologies with 32 years of experience in automation and controls and 14 years of experience in consulting and systems integration. He has expertise in front-end loading (FEL) analyses and DCSs, as well as extensive knowledge on various automation platforms and software from Rockwell Automation, Siemens, Emerson, Intellution and Wonderware. He also has worked in food and beverage, chemical/petrochemical, oil and gas, water treatment, pulp and paper and power generation industries. Maverick Technologies is a member of the Control System Integrators Association (CSIA).