A new power plant can arrive with roughly 500 smart field devices or more, nearly all of them holding diagnostic data that often never reaches the control room or the maintenance server. At the 2026 Ovation Users’ Group Conference in Pittsburgh, Emerson’s Tom Mullins, strategic account sales director for Emerson Actuation Technologies, and Tinh Phan, Emerson’s Reliability Solutions business subject matter expert, showed how one utility fixed that with a joint specification called a field device connectivity technical file.

Why It Matters

Most devices are smart, but the data is often stranded in the device. What is usually missing is written instructions, carried through procurement and design, that say which data comes out, where it lands, and what someone does with it. Without the instructions, the asset management software ships uninstalled or installed but not utilized, the input/output cards get ordered without HART capability, and the plant starts up with 4-20 milliamp signals and nothing else. Enabling HART and reconfiguring those points afterward is possible, but it is rework and normally does not get prioritized or funding.

Key Takeaways

• Rosemount developed HART in the mid-1980s, yet many new plants are still specifying old 2000’s era specification designed   that treat it as a 4-20 milliamp loop only.
• HART analog output wiring to a motor-operated valve replaces the traditional eight to ten discrete wires, cutting wires and connection points by about 80 percent.
• The technical file specifies device model numbers, configuration, wiring, control logic, alert settings, and the Ovation and AMS Device Manager integration for each device family.
• Focusing on the data that’s important for operational performance also feeds the Ovation Virtual Advisor and Ovation AI Agents industrial AI for improved decision-making.

Why New Plants Still Arrive Unconnected

Tom laid out the history without softening it. Smart devices were seen as difficult to manage in the field. Maintenance practice was run to failure. AMS Device Manager was frequently ordered alongside the control system, then delivered without configuration, sometimes as a separate transaction handled later by a partner. And the current build wave is moving fast enough that contractors are reusing specifications written for the 2000 peaker plants.

Tinh flagged the procurement consequence directly. Quote an old specification, and you get input/output cards without HART support, which means engineering rework, redrawn wiring, and an asset management system with nothing to talk to. Check what the cards support before the order goes out.

There is a structural problem too. A natural gas greenfield project can involve 18 independent commercial relationships across the end user, the engineering, procurement and construction firm, the turbine and boiler original equipment manufacturers, and five separate Emerson business units. Device expertise sits inside those units. The people writing the control system specification are not the people who know what a torque alarm means. Add the manuals: 32 pages for the Fisher FIELDVUE DVC Digital Valve Controller, 68 for the Bettis XTE Electric Actuator, and 132 for a Rosemount Transmitter, and it becomes clear why nobody was volunteering.

What Goes into the Technical File

The file is a specification document, jointly owned and signed by Emerson and the end user, maintained with revision history. It opens with purpose, scope, and order of precedence, because the data sheet usually rules and everyone downstream needs to know that. From there it covers the asset management system (selection, architecture, installation, base configuration, order guide, alert optimization, device templates) and then each device family in turn: electric actuators, Fisher FIELDVUE digital positioners, Rosemount pressure, temperature and level, and flow meters.

Each section handles selection, field device configuration, control logic and wiring, position feedback, and integration with both the power plant control system and the maintenance server.

It gets specific. The order guide gives the sample part number, down to the option codes, that produces the HART variables the file calls for. Alert optimization goes device by device. Out of the box, a transmitter enables a long list of alerts; the file specifies the seven that stay on for a Rosemount 4051 Pressure Transmitter, focused on device health. As Tinh put it, bad data in produces bad output, and any artificial intelligence effort downstream will faithfully process the noise you feed it.

Deciding What Operators See and What Maintenance Sees

This is where the utility’s people did the work. Operations and mechanical teams reviewed proposed variable lists device by device and edited them. For a Fisher FIELDVUE digital valve controller, the Ovation Distributed Control System shows travel, internal temperature, differential pressure, drive signal, supply pressure, and position. For a Bettis XTE, position and torque as a percentage, so an operator can trend a valve that was drawing 40 percent torque two weeks ago and is now approaching 100.

The file also defines what each variable means in plain terms on the operator screen. Drive signal matters to anyone who has worked on a positioner, and it means nothing to an operator who has never been told. AMS Device Manager carries the deeper set for maintenance, including snap-on software such as the DCMlink software for actuator torque curves and the ValveLink software for packing friction, supply pressure, and cycle count.

Getting that data off the control network was the utility’s other priority. Their instrumentation and control engineering field support manager explained that system owners responsible for long-term equipment support do not walk into the control room to check diagnostics. The AMS Device Manager data server publishes device parameters, alerts, health values, and calibration results upward using MQTT, a lightweight publish-and-subscribe protocol. Her advice, echoed by Tinh: bring information technology into the design conversation early, because certificates and ports are not a startup-week problem you want to discover.

How the File Gets Built, and Where It Pays

The process was a joint team, an agreed end-user goal, a defined operational and information technology architecture, device subcommittees to prioritize HART variables, then rollout to procurement, projects, and management, and finally the specification handed to the turbine and boiler original equipment manufacturers and the engineering firm—monthly one-hour meetings for a year. The internal selling was the hard part; operations and maintenance benefits had to be explained to a design team already sending specifications out the door.

The returns show up in two places. On project execution: pre-HART tagging at the manufacturer so devices self-identify at commissioning, AMS templates for consistent setup, roughly 80 percent fewer wires and connection points on HART analog output runs, and technical clarity among the valve supplier, end user, engineering firm, and original equipment manufacturers.

On operations: standardized configuration, stored diagnostics, updated maintenance procedures, and fleet-wide trending. That last point drove several of the utility’s use cases, including reducing unnecessary valve entries and watching transmitter temperature to catch freeze protection that has stopped working.

One practical note from Tom for anyone considering this: the format and roughly 99 percent of the structural work already exists. And Tinh’s caution stands: the file only pays off if maintenance procedures are updated to use what it delivers.

Bring this into your next project. Explore the Ovation Automation Platform to see how field device data becomes operator insight and maintenance action, then start the conversation with your Emerson team before the next specification goes out.