Industrial monitoring for the mid-market — retrofit, don't rip and replace

The shape of the customer

A 5–100-person plant. Two to fifteen production lines. Mix of vendors on the floor — usually some Siemens S7, some Allen-Bradley CompactLogix or ControlLogix, sometimes Mitsubishi or Omron, often a few Modbus-only smart sensors and an Ignition or FactoryTalk install that someone deployed in 2017 and nobody's fully sure how it's licensed anymore.

The plant manager wants one screen. They get five. The IT/OT lead wants alarms in Slack. They get nothing or get them by SMS through a 2014-era pager service. The owner wants to know what a "ripped and replaced" SCADA quote would cost. The integrator says $230k–$690k before they've finished the kickoff slide.

This is the customer Sutrace is built for, and this page is the playbook.

Why retrofit beats rip-and-replace

E Tech Group's guidance on modernizing legacy control systems opens with a line that should be on every mid-market plant manager's wall: modernization without a forklift upgrade is not just possible — it's the default for plants under 100 people. They argue, correctly, that ripping working PLCs to standardize a stack you don't yet need is the most expensive mistake a small plant can make.

Live Automation's retrofit playbook goes further: they treat retrofit as the primary delivery model. Drives get replaced when they fail. Controllers get migrated when they EOL. SCADA and dashboards — that's where you can change first, because the dashboard layer is the cheapest layer to swap.

The corollary is that observability is the ideal retrofit surface. It doesn't touch the safety system. It doesn't require a line stop. It's read-only on day one. And if it works, the savings show up in two months instead of two years.

The TCO that gets quoted

MachineCDN's 2026 SCADA alternatives roundup put real numbers on what a fresh, traditional SCADA deployment costs a mid-market plant in year one:

$230,000 – $690,000 all-in, including software licenses, integrator hours, panel upgrades, server hardware, and first-year support.

That's a real range from real quotes. The low end assumes Ignition Unlimited and a small integrator footprint. The high end is Wonderware/AVEVA or FactoryTalk View SE with a Tier-1 integrator and a fresh server cluster.

Sutrace's pitch is simple: we are not a $230k SCADA. We are an observability layer that costs a small fraction of that, deploys in a week, and runs alongside whatever you've already got. If you eventually need an HMI runtime on a panel, buy Ignition or keep FactoryTalk View SE. We're the dashboard, the alarms, and the data layer — not the runtime HMI.

The 10 industrial protocols Sutrace speaks

We also ingest the non-industrial signals a mid-market plant cares about: OTel traces from the MES, Prometheus metrics from the cloud, Cloudflare uptime checks for the customer portal, and AI-agent traces from anything LLM-shaped on the back end.

That last category matters more every quarter. The plant manager who used to ask "is the line up?" now asks "is the line up and is the order intake API up and is the demand-forecast agent retrying?" One dashboard, three answers.

A typical 90-day rollout

Week 1 — read-only edge

Drop the Sutrace edge agent on a Raspberry Pi or a small x86 box on the OT VLAN. Configure it as a read-only OPC UA client (or Modbus client, or both). No firewall changes outbound except a single TLS connection to the EU cloud. No PLC reconfiguration.

Week 2 — first 50 tags

Pick 50 tags that matter: line speed on each line, scrap counter, key motor currents, the boiler temperature, the air-comp pressure, the chiller setpoint. We use the Tatsoft top-8 SCADA roundup's "first 50 tags" guidance — start with what an operator can read off the existing HMI in 60 seconds, not a tag database export.

Week 3 — alarms in Slack

Threshold + rate-of-change + flat-line detection. Route to Slack and (optionally) PagerDuty. The first time a chiller flat-lines for 4 minutes at 03:14 and the on-call gets a Slack message, the deal closes itself.

Week 4 — software side

Connect OTel from the MES. Connect Prometheus from the cloud. The plant manager now sees the OT and IT picture in one view.

Weeks 5–8 — the rest of the plant

Expand from 50 tags to 500. Add the BMS via BACnet. Add the diesel genset via J1939. Add the inverter array via SunSpec. Each new protocol is a config change, not a project.

Weeks 9–12 — drop what's redundant

Now the plant has parallel coverage with the legacy SCADA. Decide which seats to drop. A typical mid-market customer drops 1–3 FactoryTalk View SE seats or a Wonderware client license. That's $14k–$50k/year recovered.

Where this approach doesn't fit

Honest section, like always:

• Greenfield process plants needing a DCS. Buy PlantPAx or DeltaV. Sutrace is not a DCS.
• FDA/GxP-validated production lines mid-validation cycle. Don't add a new vendor in the middle of validation. Wait for the next cycle.
• Plants where SCADA = HMI runtime on a bolted panel. Keep your panel HMI runtime. Use Sutrace for the dashboards and alarms that aren't on the panel.
• Air-gapped fully isolated networks with no outbound TLS. Talk to us about the self-hosted bundle; this isn't our default.

Cybersecurity note

The Industrial Control Academy's PLC cybersecurity guide and CISA's Iranian-actor PLC advisory make the same point: exposed PLCs are a 2026-era problem, not a 2014 one. Sutrace's edge agent is the opposite of exposing the PLC — it pulls data outbound over TLS, with the PLC remaining on its isolated VLAN. There is no inbound port. The PLC never sees the public internet.

Pricing and procurement

See /pricing. One price, all protocols, EU residency, signed DPA on day one. No per-tag fee, no per-seat creep, no module up-charges.

For an honest comparison against the incumbents see:

• Sutrace as an Ignition SCADA alternative
• Sutrace as a Rockwell FactoryTalk alternative
• Retrofit vs. rip-and-replace

Further reading

• PLCtalk: PLC remote monitoring — the working integrator's perspective
• PLCtalk: Cloud SCADA / HMI for remote monitoring — what mid-market is actually evaluating in 2025
• OPC UA explained for people who only know REST