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Associate
September 21, 2026
Question

32UI (Universal Input), 16 AO (Analog Output) and 16 DO (Digital Output) over RS485 communication in a Daisy chain

I am not getting any IO expansion Module which can support these feature as

32UI (Universal Input), 16 AO (Analog Output) and 16 DO (Digital Output) over RS485 communication in a Daisy chain

Universal Inputs

  • 0-5V DC
  • 0-10V DC
  • 0-20mA / 4-20mA
  • 5kΩ Thermistor
  • 10kΩ Thermistor
  • RTD (100Ω / PT100/PT1000)
  • Dry Contact / Binary Input
  • Pulse Count Input

Universal Outputs

  • 0-10V Analog Output
  • 0-20mA / 4-20mA Analog Output
  • Relay / Binary Outputs

Please suggest

5 replies

mƎALLEm
ST Technical Moderator
September 21, 2026

Hello,

Nothing to do with STM32 and seems to be a very specific hardware. 

Need to develop your own board or look for modules for each function and assemble them to construct the needed module.

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.
Andrew Neil
Super User
September 21, 2026

This is ST’s community, for help with ST products - I don’t think ST has any such product as this?

I think you’ll need to search general (industrial) electronics catalogues; may be find an (industrial) electronics general forum …

Are you looking for an off-the-shelf, ready-built product?

 

https://www.google.com/search?q=Universal+Input%2C+Analog+Output%2C+Digital+Output+over+RS485

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
C2ChandanAuthor
Associate
September 22, 2026

Thanks for your response. We are evaluating a Building Automation I/O Expansion system. The requirement is approximately 28 Universal Inputs, 16 Analog Outputs and 16 Digital Outputs as a one stack up also can be extended to 224 signals point connected over an RS485 daisy chain. We are trying to determine whether an off-the-shelf industrial I/O expansion system exists or whether a custom STM32-based design along with signal conditioning is more appropriate. Any recommendations for industrial universal I/O expansion vendors would be appreciated.

Andrew Neil
Super User
September 22, 2026

 Any recommendations for industrial universal I/O expansion vendors would be appreciated.

As noted, that’s off-topic for this community.

Have you tried putting “industrial universal I/O expansion vendors” into your favourite internet search engine or AI ?

My previous google link also found a few ...

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.