What is Wireless SCADA and How Does it Work?

Wireless SCADA is one of the significant innovations powering automation, remote asset control and real-time data collection in industrial organisations today.

SCADA networks enable:

  • Remote process control

  • Equipment monitoring

  • Real-time data collection

  • Direct interaction with devices and equipment

  • Logging data and events

SCADA evolved from more analogue supervisory control methods during the 1960s and has since taken several leaps forward.

So to understand modern wireless SCADA and its uses, we need to travel half a century back in time.

The origins of SCADA

SCADA stands for Supervisory Control and Data Acquisition. 

The earliest iterations of supervisory control – remotely controlling assets and electrical systems – involved pilot wires. Next came stepping switches, which eventually operated on relay systems and used rudimentary encryption to enhance security.

Modern SCADA architecture

Today’s SCADA systems represent a highly advanced version of the logic behind those initial supervisory control methods.

In place of wires and relays, SCADA radio networks use a network of PLCs, sensors, software and radios to amplify the potential of remote industrial process control and data collection.


Sensors serve one purpose: monitoring data. 

In the context of wireless SCADA networks and telemetry, this might be:

  • Environmental data (air quality, soil moisture readings)

  • Equipment data (temperature, operating pressure, water levels)

  • Process data (leak detection, voltage, current)

Sensors provide a steady stream of data to PLCs and RTUs. 

PLCs and RTUs

Programmable Logic Controllers (PLCs) and Remote Terminal Units (RTUs) communicate in both directions, sending sensor data up the chain and carrying out instructions sent down the chain. 

PLCs are ruggedised computers used to control industrial equipment from individual fans and pumps through to complete assembly lines. Smart PLCs can be programmed to automate simple tasks based on logic processes, freeing up operator time and improving failure handling.

In remote applications, numerous PLCs spread over a wide area either connect with the SCADA system wirelessly or use an RTU to handle communication protocols.


The Human-Machine Interface (HMI) or SCADA software is the operator’s window into the SCADA system, and how the operator communicates with PLCs and RTUs.

A graphical interface translates data into understandable diagrams, charts and alerts, giving the operator the information they need to make decisions.

Wireless SCADA radio networks

There is one crucial layer still to explore.

First-generation SCADA systems largely relied on independent networks and proprietary communications protocols.

Skip forward a few generations, and wireless SCADA networks now interface with web-based HMIs that allow global teams and remote operators to:

  • Reduce downtime

  • Collaborate on decisions

  • Optimise efficiency

  • Improve safety

All without needing to step foot on site.

However, wireless SCADA systems depend on radio communication, especially in large-area networks, remote locations and inaccessible or hazardous sites.

The devices transmitting information between PLCs and HMIs therefore become a crucial component – if not the most crucial – in a reliable and effective wireless SCADA network.

Upgrading to wireless SCADA 

Many operations in the Mining, Rail, Logistics, Environmental and Manufacturing industries are upgrading to wireless SCADA systems. 

Wireless infrastructure reduces maintenance costs, minimises environmental risks and removes any need for trenching or conduits.

Thankfully, most existing SCADA systems can “go wireless” without reconfiguring the entire scheme or investing in new software and training. 

Wireless SCADA radios and I/O modules like those that STI Engineering designs and manufactures can power analogue, digital and relay applications to take the hard work out of wireless SCADA systems.

Our solutions enable telemetry and I/O applications over wide area data networks, including Mining and Resources projects, Logistics, Agriculture, Transport and Utilities, where reliable communication is critical.

We even offer a complete plug-and-play solar-powered SCADA radio solution for remote areas without mains power access.

You can see our wireless SCADA solutions in more detail on our website or contact STI Engineering to discuss your SCADA radio requirements.