many PT1000 connections

[partach]

Hi,

For a client we want to use the revpi to do building control. The building has many pt1000 temperature sensors (20+). Currently the AIO module can only serve 2. As it is also an expensive module and the fact you maybe we don't use many of the other ports of such AIO module, it feels not matching. Is there a module in planning that only does temperature (PT1000/PT100 like)? Like the ability to connect 8 or 9 temperature sensors on one module?
What would be another alternative?
If there is not a direct solution am thinking of this direction: https://www.iot-solution.com/rtd-input- ... 269p1.html?

[Amar]

Hi,
The AIO module is indeed not the ideal fit for a pure temperature acquisition use case at scale — you are right that 2 channels is limiting and the module cost is hard to justify if you only need RTD inputs.

There is currently no dedicated multi-channel temperature input module planned for the RevPi ecosystem that we can announce publicly.

The most practical path for 20+ PT1000 sensors is to use external RTD modules connected via Modbus RTU (RS485) or Modbus TCP, which the RevPi supports natively.

Modbus RTU (RS485) options to evaluate:
- Datexel DAT3019 — 8-channel, Pt100/Pt1000, 16-bit, RS485 Modbus RTU (note: 2-wire only)
- LucidControl Lucid485 RI8 — 8-channel, Pt100/Pt1000, RS485 Modbus RTU, German vendor
- ComWinTop CWT-TM-8PT — 8-channel, Pt100/Pt1000, 2 or 3-wire, RS485 Modbus RTU
- BLIIoT M340 (the module you linked) — 8-channel, Pt100/Pt1000, 2 or 3-wire (verify CE certification before industrial use)

Modbus TCP options to evaluate:
- ICP DAS ET-7215 — 7-channel, Pt100/Pt1000, daisy-chainable Ethernet, auto 3-wire compensation
- Datexel DAT8014 — 8-channel, Pt100/Pt1000, Modbus TCP, galvanic isolation, built-in web server

If mixed I/O is needed alongside temperature:
The Wago 750-series with 4-channel RTD slice modules on a Modbus TCP coupler is an option worth looking at — more expensive per channel but very flexible and well-supported.

Integration on the RevPi side:
- Built-in Modbus Master (piModbus / Node-RED) — works for simple setups with few slaves
- CODESYS Modbus RTU/TCP Master — better suited for larger deployments with many slaves and complex polling
- RevPi Modio + Python (pymodbus / minimalmodbus) — if a pure Linux/Python environment without a PLC runtime is preferred

Multiple RS485 modules can share one bus using different slave addresses, so scaling to 20+ sensors across 3–4 modules is straightforward on a single RS485 port.

Regards,
Amar

[partach]

Thank you very much for the quick and good reply.
Too bad it is not on a confirmable roadmap for revpi (yet).
Love your products!