Industrial Telemetry: What It Is and When to Use LoRa

Telemetry means measuring something in one place and receiving that measurement somewhere else, without anyone having to go and read it. In a plant, it is the temperature of a cold room, the consumption of an electrical panel or the level of a tank arriving on their own at a dashboard or an alarm. It has three parts: the sensor that measures, the network that transmits and the system that stores the data and raises alerts.

What is telemetry? #

The word means measuring at a distance. It is used in truck fleets, in Formula 1, in water networks and in software. In industry, telemetry is the automatic collection of physical variables from equipment and processes that are remote or spread out, so you can see their status and react in time.

How does a telemetry system work? #

1. Sensor or meter: temperature, energy, pressure, level, flow, vibration or a pulse counter.
2. Transmitter: turns the measurement into a message and sends it over cable or radio.
3. Network: Wi-Fi, cellular, LoRa or industrial cable.
4. Central unit: receives the messages, stores them with a timestamp and detects when something has stopped reporting.
5. Dashboard and alarms: what people see, plus the alerts when a variable goes out of range.

Which network makes sense in a plant? #

LoRa is the best fit for plant telemetry: it reaches far, uses little power and has no monthly plan. Its limit is that it sends short messages, so it works for readings, not images. The difference between LoRa and LoRaWAN, and how to size a network, is covered in the industrial LoRaWAN guide.

How is it different from SCADA? #

A SCADA system supervises and also controls: it opens valves, starts motors and changes setpoints. Telemetry only measures and alerts. Many plants run SCADA on the main process and telemetry for everything left outside it: cold rooms, electrical panels, tanks, wells. The parts of a SCADA system are explained in what is SCADA.

What do plants measure with telemetry? #

• Temperature in cold rooms, tunnels and incubators. See cold room temperature monitoring.
• Energy per panel or per machine, to know what consumes power and when. See Chile's energy efficiency law.
• Water: tank level, flow and pressure.
• Production: pulse counters on machines that have no connected PLC.

How we do it at iGromi #

Our panel-level energy meters read consumption per phase and transmit it over LoRa to a central unit connected to the plant's Edge PC. The central unit polls each node in turn, so it knows instantly which one has stopped responding. From the Edge, the data is cross-referenced with production and temperature on the same dashboard, and it is available to the ERP.

We learned two things in the field. First, real range is measured in the plant, not on the datasheet: a concrete wall or a metal cold room changes everything. Second, what fails most is not the sensor but the node's power supply, so you design for it from the start.

Frequently asked questions #

Are telemetry and IoT the same thing?

They are close. Telemetry is the idea of measuring at a distance; industrial IoT is today's way of doing it, with connected sensors sending data to a platform.

Do I need internet at every measurement point?

No. With LoRa or cable, the sensors talk to a central unit inside the plant; only the central unit needs an internet connection, and only if the dashboard is viewed from outside.

What happens if communication drops?

A good system tells you the sensor has stopped reporting, instead of showing the last value as if nothing happened. It is also worth asking whether the node stores readings while it is disconnected.

Can I read a PLC through telemetry?

Yes, if the PLC has a communication port. Its registers are read without modifying the program and transmitted like any other measurement.