Short answer: Design an industrial IoT device around four decisions: connectivity chosen by the installation site (wired Ethernet or fieldbus in cabinets; Wi-Fi or private 5G on the plant floor; LoRaWAN or NB-IoT for battery devices over wide areas; BLE near a gateway; LTE-M for roaming assets); a power budget that matches the source (machine-powered with protection, PoE, or battery with duty cycling for multi-year life); security by design with secure boot, encrypted storage, signed updates and a unique device identity, which the EU Cyber Resilience Act makes a market requirement for connected products; and manufacturability so the device can be built, tested, provisioned and updated at scale. Comtec Labs designs, prototypes and manufactures such devices as one project.
Connectivity by site
| Situation | Recommended | Notes |
|---|---|---|
| Inside a control cabinet, machine-powered | Ethernet, Modbus TCP/RTU, CAN, IO-Link | Cheapest and most reliable; use existing infrastructure |
| Plant floor, mobile or hard to cable | Wi-Fi 6, private 5G | Roaming and latency need testing on site |
| Battery, low data rate, kilometres | LoRaWAN, NB-IoT | Seconds of latency, bytes per message, years of battery |
| Battery, gateway within tens of metres | Bluetooth Low Energy | Phone commissioning, low cost |
| Roaming assets, vehicles, containers | LTE-M, with GNSS | Carrier contracts, SIM/eSIM logistics |
Power budget
- Machine-powered 24 V: reverse polarity, surge and overvoltage protection on the input; galvanic isolation where ground loops are likely.
- PoE: a clean option for Ethernet devices; design for the IEEE 802.3af/at class you need.
- Battery: measure the real duty cycle (sleep, sample, transmit); a node sleeping at microamps and transmitting for a second an hour lasts years, one that keeps a radio listening lasts weeks.
- Energy harvesting: solar or thermal only when the average budget is tiny and the storage is sized for the dark season.
Security by design
Secure boot with signed firmware, encrypted credentials in a secure element or protected flash, mutual TLS to the backend, a unique device identity provisioned on the production line, signed over-the-air updates with rollback, a debug port that can be locked, and a vulnerability handling process. The EU Cyber Resilience Act (Regulation (EU) 2024/2847) turns these from good practice into conformity requirements for products with digital elements sold in the EU, with the main obligations applying from 2027. Designing them in now avoids a redesign later.
Environment and manufacturability
- Temperature range, sealing (IP65/67), conformal coating and surge protection for outdoor and machine-mounted devices.
- Antenna design and placement validated on the enclosure, then radio pre-compliance under the Radio Equipment Directive.
- Test points, automated functional test and line provisioning of keys, certificates and serial numbers.
- Component strategy with second sources for radios and MCUs, which are the parts most exposed to allocation.
Key facts
- Site conditions, not data rate, decide the right radio for most industrial IoT devices.
- A duty-cycled LoRaWAN or NB-IoT node commonly reaches 5–10 years on a single cell.
- The EU Cyber Resilience Act makes secure boot, updates and vulnerability handling market requirements for connected products.
- Comtec Labs designs, builds and provisions industrial IoT devices in Vaasa, Finland, from sensor front-end to series production.
How to start
Describe the site, the data, the power available and the platform that will receive the data. We propose the connectivity and power architecture, a security plan aligned with the Cyber Resilience Act, and a prototype schedule, then take the device to series production on our own lines.
Frequently asked questions
Which is better for industrial IoT: LoRaWAN or NB-IoT?
LoRaWAN when you run your own gateways and want no carrier dependency; NB-IoT when you want carrier coverage without infrastructure. Both suit battery devices sending small messages.
Do we need a secure element?
For devices that hold credentials and must resist physical attack, yes; for cabinet-mounted devices an MCU with hardware crypto and protected flash can suffice. The Cyber Resilience Act risk assessment decides.
Can Comtec Labs certify the radio?
We design and pre-test, then manage formal RED testing with an accredited laboratory, or use pre-certified modules when volume and schedule favour it.
Can you manage device provisioning at scale?
Yes. Keys, certificates and identities are generated and injected on the production line and reported per serial number.
Ready to reduce PCB surprises?
Comtec Labs offers a full suite of services to streamline your workflow:
PCB design service
PCB prototyping service
PCB component sourcing
PCB component assembly
PCB testing service
PCB repair and modifications
Printed circuit board production
PCB mass production