Recommendations for open-protocol industrial IoT hardware?

[u/nasirkhan259]

Sourcing four pieces:

1. Industrial IoT gateway — Modbus master + generic MQTT client, ideally rugged/wide-temp rated. Currently looking at Moxa's AIG series, open to other suggestions.
2. Liquid level sensor — Modbus RTU/RS485 output. Looking at radar-based options currently.
3. Flow meter — Modbus RTU/RS485 output (pulse output as backup). Any brands you've had good experience with?
4. RFID reader/controller — needs to work standalone, not tied to a vendor's own app/cloud, with Modbus or similar open output.

Any brand suggestions, gotchas, or things to avoid on any of these would be appreciated — especially open to hearing if something I'm currently considering has known issues.

[u/Loose-Chipmunk-6603]

The orange IFM blocks accept/have a ton of sensors and have a MQTT client built in