The confusion, and why it matters
"We already have SCADA — why would we need an IoT platform?" is one of the most common questions we get, and it's a fair one. The terms overlap in marketing and both end up showing you values on a screen. But buying the wrong one for the job — or assuming one replaces the other — wastes money and disappoints. The distinction is actually simple once you separate control from visibility.
One-line test: if the job is to control a process in real time, that's SCADA. If the job is to see, analyse and act across many assets, sites and data sources, that's an IoT platform. Different jobs — which is why they coexist.
What SCADA is for
SCADA (Supervisory Control and Data Acquisition) is an operational control system. It runs the process: reading PLCs and instruments in tight, deterministic loops, presenting operators a control HMI, and letting them supervise and control plant in real time — open a valve, start a pump, change a setpoint. It's typically on-site, mission-critical, and engineered for reliability and fast control. If you operate a treatment works, a substation or a production process, SCADA (or a DCS) is how you run it. That's its strength — and you don't replace it casually.
What an IoT platform is for
An Industrial IoT platform is a data, visibility and analytics layer. Its job is breadth, not control: pull data from many sources — SCADA, PLCs, standalone sensors, meters, even legacy machines that were never connected — across many sites into one place, then turn it into trends, dashboards, alerts, reports and integrations with ERP/MES. It's built for analytics over time, remote and multi-site visibility, and connecting the islands. It often runs in the cloud (or on-prem), buffers at the edge for poor connectivity and load shedding, and is designed to add cheaply to equipment you already own.
Side by side
| SCADA | IoT platform | |
|---|---|---|
| Primary job | Supervise & control the process | Visibility, analytics & integration |
| Real-time control | Yes — deterministic loops | No — it observes and alerts |
| Scope | A site / process | Many assets, sites and sources |
| Data horizon | Live operations, shorter history | Long-term trends & analytics |
| Typical home | On-site, mission-critical | Cloud or on-prem, edge-buffered |
| Best at | Running the plant | Seeing across the plant(s) & the business |
Which do you need?
- You need to control a process → SCADA (or a DCS). An IoT platform won't do real-time control and shouldn't pretend to.
- You have data trapped in silos — SCADA on one plant, standalone meters, sensors that don't talk to each other → an IoT platform unifies them.
- You have old equipment with no SCADA → an IoT platform reads what the machine already produces (see OEE without a PLC) without a full control-system project.
- You have many remote sites — pump stations, reservoirs, boreholes → an IoT platform with edge buffering and low-power connectivity is built for that; SCADA over flaky links is painful.
- You need analytics, reporting or ERP/MES integration → that's the IoT platform's home turf.
- You already run SCADA and want plant-wide or cross-site visibility and trends → add a platform alongside it, fed partly from SCADA.
They work together
The healthiest pattern in most operations is both: SCADA keeps controlling the process exactly as it does today, and the IoT platform sits alongside — taking a feed from SCADA where it exists, reading PLCs and sensors directly elsewhere, and pulling standalone and legacy assets into the same picture. You get control where you need it and visibility across everything, without ripping anything out. The platform becomes the single pane of glass over a plant (or a fleet of sites) that SCADA alone was never designed to provide.
That's exactly what the in-house addaNet platform does — vendor- and PLC-agnostic, integrating with existing SCADA and controllers over standard protocols (OPC-UA, Modbus, MQTT), reading legacy and remote assets too, and buffering at the edge for South African power and connectivity. It's the visibility-and-analytics layer over what you already run — not a replacement for the control system that keeps your plant safe. For the bigger picture, see our guide to Industrial IoT in South Africa.
Frequently asked questions
What's the core difference between SCADA and an IoT platform?
SCADA is a control system — it supervises and controls a process in real time, on-site. An IoT platform is a visibility-and-analytics layer — it gathers data from many sources and sites (including SCADA) into one place for dashboards, trends, alerts, reporting and business-system integration. Control vs visibility: different jobs.
Does an IoT platform replace SCADA?
Usually not. SCADA controls your process and is mission-critical; you rarely rip it out. An IoT platform sits alongside it — taking a feed from SCADA where it exists and reading other assets directly — to give plant-wide and cross-site visibility, analytics and integration that SCADA wasn't designed for.
We already have SCADA — why add an IoT platform?
For breadth and analytics: unifying multiple sites and standalone assets into one view, long-term trending, remote/off-grid monitoring with edge buffering, and feeding data into ERP/MES. SCADA is excellent at running a process; the platform is built to see and analyse across many of them and connect to the business.
We have no SCADA, just old machines. Where do we start?
An IoT platform is the lighter starting point. It reads the signals old equipment already produces — motor current, counts, stack lights — and remote sensors, without a full control-system project. You get visibility and alerts quickly, and can add control systems later only where you actually need to control something.
Can an IoT platform control equipment, like SCADA does?
It shouldn't be relied on for real-time, safety-critical control — that's SCADA/PLC territory with deterministic loops. IoT platforms can trigger non-critical actions and alerts, but the control of a process should stay in the control system. Use each for what it's built for.