Process blending control retrofit - an outline.
Illustrative example of the kinds of controls work we take on. The project described here is an archetype, not a portfolio — specific client work is discussed under NDA.
This is an outline, not a delivered case study. It describes the shape of a typical engagement of this kind: the questions we ask up front, the work involved, and how the cutover tends to be sequenced. Actual scope, schedule, and outcomes vary by site.
What the operator sees on the mix screen.
The recipe library on the left, the live mix in detail on the right. Both live in the same HMI, on the same screen, so the operator can queue and start mixes without digging through menus.
The HMI screens below are conceptual mockups for illustrative purposes only. They are not real-life screenshots from a live customer system or deployed plant HMI.
An aging plant, a glitchy computer, and a busy paving season ahead.
Continuous drum plants with legacy control systems are often partly serviceable and partly at risk: some field hardware may still have useful life, while the PLC, HMI, or support computer may be hard to maintain. Another paving season is just around the corner, and the owner needs a clear view of what can be kept and what should be modernized.
The constraint tends to be the same: a winter shutdown window and a non-negotiable paving start date in the spring.
What the work typically involvesOne control platform, one HMI, one alarm philosophy.
- A PLC platform selected with the client, which may be a new controller or integration with suitable existing I/O
- Remote I/O or field-device integration sized around the plant's existing wiring and hardware condition
- Operator HMI station with dual monitor set up
- Asphalt-oriented custom 3D graphics HMI built from our reusable components — mix, overview, materials, totals, calibration
- Alarm rationalization aligned with ISA-18.2
- An on-prem SQL Express historian, with optional cloud KPI feed
- VPN-based remote support arranged in place of exposed RDP
- Operator training
From shutdown to first paving truck.
The exact length depends on the plant. The phases below are usually present in some form.
Phase 1 · Strip & pre-wire
Hardware is removed only where needed; new panels, controllers, or remote I/O are mounted where required, and serviceable field wiring is carried forward.
Phase 2 · Loop checks & safety
Every I/O point is exercised. Drive, motor interlocks and safety systemstested. All with a qualified technician on site.
Phase · Calibration
Calibration of all ingredient channels is completed. Single or multi-point calibrations available.
Phase 4 · Dry-run mix
A small number of mix designs produced to storage silos. Totals reconciled against the truck scale before any customer trucks are loaded.
Phase 5 · Operator dry-run
Operators run the full HMI through a typical paving morning — start-up, mix change, silo drop — before the first paving day.
Phase 6 · Hand-off & first paving day
We aim to be on site for the first customer truck, with remote support arrangements after that.
Common project specs
- PLC: Siemens, Rockwell, or other suitable platform
- I/O: existing or new I/O sized to the plant
- HMI: FactoryTalk Optix
- Network: PROFINET, PROFIBUS, EtherNet/IP
- Historian: SQL Express, ODBC-Compliant
- Cloud: AWS, AZURE optional
Questions we usually ask up front
- What is the current PLC and HMI, and roughly how old?
- How long is the shutdown window?
- What is the non-negotiable start date?
- What dispatch / ticketing system is in use?
- Are the field wiring drawings up to date?
- What does the operator group look like on day one?
Service areas and offerings this project draws on
Plant Control (PLC)
PLC programming for the plant, written against IEC 61131-3 conventions.
Learn more ▦Operator HMI
Operator HMI designed against ISA-101, with custom 3D graphics representing plant layout.
Learn more ▦Process Blending
Reusable process blending components used as a starting point for site-specific screens.
Learn morePlanning something similar?
If a drum plant retrofit is on the radar, a short conversation about the shutdown window and current PLC platform is usually a good place to start.
Get in touch