PLC and datalogger integration
PLC and datalogger integration over MQTT, Modbus and OPC UA
Collect process data from the equipment you already have, store it, visualise it and act on it, without replacing your PLCs or dataloggers.
500+ customers · 100,000+ active sensors · Trusted by Akademiska Hus, Vattenfall, LKAB and HSB
How the data flows
From the shop floor to your decisions.
Equipment
PLCs, SCADA systems and dataloggers in the field or on the shop floor.
Connect
MQTT, Modbus TCP or OPC UA, whichever the device speaks.
Sensor-Online
Stores, visualises, alarms and reports on every value.
Your systems
Dashboards, alerts, the API and tools such as ERP, BI and maintenance systems.
Three ways to connect
Use the protocol that fits each device.
MQTT for dataloggers
Dataloggers on 4G, 5G, NB-IoT or Wi-Fi publish to the built-in MQTT broker, and Sensor-Online subscribes to the topics. MQTT is lightweight and suits unreliable, low-bandwidth networks.
Modbus TCP for PLCs
Read process values from existing control systems, and write setpoints back.
OPC UA for SCADA and industrial IT
Connect OPC UA servers and clients in both directions and bridge OT and IT in one data layer.
Which protocol for which job?
A quick guide.
| MQTT | Modbus TCP | OPC UA | |
|---|---|---|---|
| Typical source | Dataloggers and remote devices | PLCs and meters | SCADA and industrial servers |
| Direction | Device publishes, platform subscribes | Read and write | Read and write |
| Network | Mobile data, Wi-Fi, low bandwidth | Local network | Local network |
| Good for | Remote sites and many small devices | Process values and setpoints | Structured industrial data |
What you get once the data is in
Everything you need to run the operation, built in.
Time-series storage
Keep years of history and query it instantly.
Dashboards
Real-time charts, gauges, maps and tables for operators and managers.
Alarms
Rule-based alerts by e-mail, SMS, webhook and MQTT.
Reports
Scheduled reports in PDF, Excel or CSV.
Protocol transformation
Receive on one protocol and deliver on another.
Automation
Build flows with the rule engine, Node-RED and n8n.
Need a datalogger?
Connect any sensor over any network.
The yDoc ML-525 is a universal multipurpose IoT datalogger that connects any sensor and any network, and works with Sensor-Online out of the box.
See the yDoc ML-525 datalogger →Related features
Connect LoRaWAN sensors to PLC and SCADA
Read more →JavaScript rule engine
Read more →Node-RED and n8n automation
Read more →Secure IoT platform with REST API
Read more →Frequently asked questions
Can Sensor-Online collect data from a PLC?
Yes, over Modbus TCP and OPC UA, with both read and write.
Does Sensor-Online include an MQTT broker?
Yes. Dataloggers and devices can publish directly to the built-in MQTT broker.
Do I need to replace my existing equipment?
No. Sensor-Online connects to the PLCs, SCADA systems and dataloggers you already have.
Can I forward the data to other systems?
Yes. Use the REST API, MQTT, webhooks, Node-RED or n8n.
Can it run on-premise?
Yes, behind your firewall, with your data staying on your own network.
Connecting PLCs or dataloggers? Talk to an engineer.
Tell us what equipment you have, and we will recommend how to connect it.
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