Question 1

Can opcua2mqtt run in air-gapped industrial plants with zero internet?

Accepted Answer

Yes, absolutely. opcua2mqtt was engineered strictly for air-gapped Purdue Model Level 2 (Cell/Area) and Level 3 (Operations) OT networks. The native Rust binary contains zero tracking SDKs, zero phone-home daemons, and zero hidden analytics. All license validations use local asymmetric Ed25519 public-key cryptography and execute 100% offline. The daemon never opens inbound listening ports and initiates network connections strictly to your configured OPC UA servers and MQTT/TSDB brokers.

Question 2

How does the perpetual license & build-date protection work?

Accepted Answer

Your perpetual license grants permanent operational rights: any binary version compiled during your active license period will run forever. Unlike predatory cloud subscriptions that brick your machines if a payment lapses, opcua2mqtt compares binary build timestamps against your entitlement date. If you decide not to renew annual maintenance, your factory keeps running without interruption.

Question 3

Which PLCs and industrial controllers are compatible?

Accepted Answer

Any OPC UA compliant server is supported, including Siemens S7-1200 / S7-1500, Beckhoff TwinCAT 2/3, Rockwell Allen-Bradley ControlLogix, Schneider Electric Modicon, ABB, Omron, B&R, and CNC controllers from Fanuc, Heidenhain, and Sinumerik.

Question 4

How does the persistent Store & Forward disk buffer handle power cuts?

Accepted Answer

In Pro and Enterprise editions, all telemetry samples are committed to an embedded disk Write-Ahead Log (WAL) before confirmation. If power fails or the broker drops, pending data remains safe on non-volatile flash. Upon network reconnection, data is replayed in chronological order with original millisecond-accurate PLC source timestamps preserved.

Question 5

What hardware can opcua2mqtt run on?

Accepted Answer

Because opcua2mqtt is written in Rust without runtime bloat, it runs on virtually any Linux or containerized target: Raspberry Pi 4/CM4, Siemens IOT2050, Kunbus Revolution Pi, Advantech UNO, Moxa UC-series, Intel NUC, or bare-metal Xeon / EPYC cluster nodes.

Question 6

How does this compare to running Node-RED for industrial telemetry?

Accepted Answer

Node-RED is great for quick prototyping, but runs on Node.js V8 which consumes 300MB - 800MB RAM, experiences unpredictable garbage collection spikes, and lacks atomic, crash-proof disk queue guarantees. opcua2mqtt runs on <50MB RAM, processes 150,000+ msg/s deterministically, and provides industrial IEC 62443 cybersecurity safeguards.

opcua2mqtt — Industrielle OPC UA MQTT Schnittstelle & Sparkplug B Edge Gateway